mercury rt v2.7 reference handbook - mercuryprogram.eu · calibration, to create a project from...

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Mercury RTⓇ v2.7

Reference Handbook

mailto:[email protected]


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Revision History

Description SW Version -

Revision

Originator Date

Draft 1.0 Jan Cepela 2010-03-05

Inclusion of opponent’s comments 1.0 Jan Cepela 2011-10-07

Document enhancements 1.1 Petr Gajdos 2012-05-18

Document enhancements 1.2 Jan Cepela 2012-06-26

Document enhancements 1.2 Petr Gajdos 2012-10-15

Document enhancements 1.2 Peter Sluka 2012-01-17

Document enhancements 1.3 Peter Sluka 2013-03-20

Added TC 1.3 Jan Cepela 2013-04-13

Features and GUI updated 1.4 Petr Gajdos 2013-08-07

Features and GUI updated 1.5 Petr Gajdos 2013-10-17

Update on current version 2.0 Adam Kostelnik 2014-02-14

Update on current version 2.0 Adam Kostelnik 2014-03-12

Update on current version 2.2 – a Jakub Rada 2014-07-03

Update on current version 2.2 – b Jakub Rada 2014-07-07

Update on current version 2.2 – c Jakub Rada 2014-07-16

Update on current version 2.2 – d Jakub Rada 2014-07-18

Update on current version 2.2 – e Jakub Rada 2014-07-23

Update on current version 2.2 – f Jakub Rada 2014-07-26

Test Rig, Vibrography and Stress vs.

Strain Graph

2.3 – a Jakub Rada 2014-08-19

Test Rig, Vibrography and Stress vs.

Strain Graph

2.3 – b Jakub Rada 2014-09-08

Added I/O services 2.3 – c Jakub Rada 2014-10-17

Update of the graphical windows 2.3 – d Jakub Rada 2014-11-12

Major overhaul 2.3 – e Mercury RT collective 2014-12-12

Update on custom expressions 2.3 – f Martin Zaleta 2015-02-26

Update on current version 2.4 – a Mercury RT collective 2015-10-12

Update on current version 2.4 – b Tomas Svojanovsky 2016-03-14

Update on current version 2.4.1 – a Tomas Svojanovsky 2016-04-04

Update on current version 2.4.1 – b Mercury RT collective 2016-08-22

Update on current version 2.4.2 – a Mercury RT collective 2016-11-02



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Update on current version 2.4.2 – b Mercury RT collective 2017-03-18

Update on current version 2.5 – a Jakub Zdeblo 2017-06-05

Document revision 2.5 – b Martin Zaleta 2017-06-15

Update on current version 2.5 – c Tomas Svojanovsky 2017-07-19

Document revision 2.5 – d Martin Zaleta 2017-07-21

Update on current version 2.5 – e Petr Stolar 2017-08-01

Update on current version 2.6 – a Michal Sicner 2018-05-15

Update on current version 2.6 – b Vladimir Veselkov 2018-07-04

Document revision 2.6 – c Martin Zaleta 2018-07-31

Document revision 2.6 - d Jakub Zdeblo 2018-09-11

Document revision 2.6 - e Martin Zaleta 2018-11-08

Update on current version 2.7 – a Pavel Ondracek 2019-01-25

Minor revision 2.7 – b Lukas Stritesky 2019-02-12

Document revision 2.7 – c Martin Zaleta 2019-02-14

Update on current version 2.7 – d Martin Zaleta 2019-04-08

Document revision 2.7 – e Roman Pavelka 2019-05-10

Minor corrections 2.7 – f Martin Zaleta 2019-05-14



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Brief Overview ....................................................................................................................................................... 9

Main Window ...................................................................................................................................................... 10

2.1 Menu Bar ............................................................................................................................................................. 10

2.2 Project Creation ................................................................................................................................................... 12

2.2.1 Save As ........................................................................................................................................................ 16

2.3 Project Panel........................................................................................................................................................ 17

2.3.1 Projects ....................................................................................................................................................... 17

2.3.2 Test. Machine ............................................................................................................................................. 17

2.3.3 Services ....................................................................................................................................................... 17

2.3.4 Cameras ...................................................................................................................................................... 17

2.3.5 Sync Box ...................................................................................................................................................... 17

2.3.6 Point Filtering.............................................................................................................................................. 18

2.3.7 Value Filtering ............................................................................................................................................. 18

2.3.8 Extensometer Calibration ........................................................................................................................... 19

2.3.9 Project Notes .............................................................................................................................................. 19

2.4 Project Controls ................................................................................................................................................... 19

2.5 Graphs Panel ....................................................................................................................................................... 21

2.6 Graph Data Panel ................................................................................................................................................. 23

2.6.1 Visual Alarm ................................................................................................................................................ 23

Scene Window ..................................................................................................................................................... 25

3.1 Camera View Controls ......................................................................................................................................... 26

3.2 Control Panel ....................................................................................................................................................... 29

3.2.1 Live Camera ................................................................................................................................................ 29

3.2.2 Thermal Camera ......................................................................................................................................... 31

3.2.3 Scene Setup ................................................................................................................................................ 31

3.2.4 Camera Calibration ..................................................................................................................................... 33

3.2.5 Coordinate System Definition ..................................................................................................................... 37

3.2.6 Large Object Calibration ............................................................................................................................. 42

3.2.7 Probes ......................................................................................................................................................... 45

3.2.8 Group Operations ....................................................................................................................................... 58

3.2.9 Parameters ................................................................................................................................................. 59

3.2.10 Seek Panel ................................................................................................................................................... 60

3.3 3D Graph.............................................................................................................................................................. 60

Import .................................................................................................................................................................. 62

4.1 Externally Measured Data ................................................................................................................................... 62

4.1.1 Measured Data Import Tool ....................................................................................................................... 62

4.2 Probes from a Project .......................................................................................................................................... 63

4.3 Settings from a Project ........................................................................................................................................ 63

Export .................................................................................................................................................................. 64

5.1 Export Graph Data to CSV and HDF5 ................................................................................................................... 64

5.2 Export Area Data to CSV and HDF5 ..................................................................................................................... 65

5.3 Export STL Model ................................................................................................................................................. 66

5.4 Export Project as Local Example .......................................................................................................................... 66

5.5 Generate Report .................................................................................................................................................. 67

Post-Processing .................................................................................................................................................... 68

6.1 Vibrography ......................................................................................................................................................... 68



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6.1.1 Amplitude/Phase tab .................................................................................................................................. 69

6.1.2 Power/Energy tab ....................................................................................................................................... 69

6.1.3 Campbell Diagram ...................................................................................................................................... 69

6.1.4 Signal Info ................................................................................................................................................... 70

6.1.5 Preview ....................................................................................................................................................... 71

6.1.6 Export .......................................................................................................................................................... 71

6.1.7 Other controls ............................................................................................................................................. 71

6.2 CAD/FEA Validation ............................................................................................................................................. 73

6.2.1 CAD/FEA Tool Window ............................................................................................................................... 73

6.2.2 Alignment of Models .................................................................................................................................. 74

6.3 FLC/FLD Analysis .................................................................................................................................................. 75

6.3.1 FLC Analysis Process ................................................................................................................................... 75

6.3.2 Area Cross-Sections Graph ......................................................................................................................... 76

Settings ................................................................................................................................................................ 78

7.1 System Settings ................................................................................................................................................... 78

7.1.1 Active Camera Libraries .............................................................................................................................. 78

7.1.2 Cameras ...................................................................................................................................................... 79

7.1.3 Synchronization Box ................................................................................................................................... 80

7.1.4 Test Rig ....................................................................................................................................................... 80

7.1.5 USB Relay .................................................................................................................................................... 81

7.1.6 Remote Presenter ....................................................................................................................................... 81

7.1.7 Report Generation ...................................................................................................................................... 81

7.1.8 Debugging ................................................................................................................................................... 81

7.1.9 Examples ..................................................................................................................................................... 82

7.1.10 Application .................................................................................................................................................. 82

7.2 Presentation Settings .......................................................................................................................................... 82

7.2.1 Graph .......................................................................................................................................................... 83

7.2.2 Color Scale .................................................................................................................................................. 83

7.2.3 Metrology Tool ........................................................................................................................................... 84

7.2.4 Recorded Data Playback ............................................................................................................................. 84

7.2.5 Post-Processing ........................................................................................................................................... 84

7.2.6 Vibrography ................................................................................................................................................ 84

7.3 Computation Settings .......................................................................................................................................... 85

7.3.1 Correlation .................................................................................................................................................. 86

7.3.2 Width Measurement .................................................................................................................................. 90

7.3.3 Calibration .................................................................................................................................................. 90

7.3.4 Full-Field Measurement .............................................................................................................................. 91

7.3.5 Marker Detection........................................................................................................................................ 92

7.3.6 Point Filtering.............................................................................................................................................. 94

7.4 Other Controls ..................................................................................................................................................... 94

Examples .............................................................................................................................................................. 95

Test Rig Configuration .......................................................................................................................................... 97

9.1 Active Test Rig ..................................................................................................................................................... 97

9.2 Doli EDC / SobriECU ............................................................................................................................................. 97

9.2.1 Test Rig Panel .............................................................................................................................................. 97

9.2.2 Preset Configuration ................................................................................................................................... 98



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9.3 Analog / Digital Input ......................................................................................................................................... 103

9.3.1 Test Rig Panel ............................................................................................................................................ 103

9.3.2 Digital Input Format Description .............................................................................................................. 103

I/O Services ........................................................................................................................................................ 105

10.1 Adding a New Service .................................................................................................................................... 105

10.1.1 Analog Output Service .............................................................................................................................. 106

10.1.2 Digital Output Service ............................................................................................................................... 107

10.1.3 DOLI Binary Serial Output Service ............................................................................................................. 109

10.1.4 Test Rig Output ......................................................................................................................................... 110

10.1.5 HP Video Service ....................................................................................................................................... 110

10.1.6 Remote Control API Service ...................................................................................................................... 110

10.2 Configuration of the Output Values .............................................................................................................. 112

10.3 Mercury RTⓇ I/O Accessories ........................................................................................................................ 115

10.3.1 DigiGauge .................................................................................................................................................. 115

10.3.2 TensoAmp ................................................................................................................................................. 115

Extensometer Calibration .................................................................................................................................. 117

11.1 Creating an Extensometer Calibration Measurement .................................................................................. 117

11.2 The Definition of the Extensometer Calibration ........................................................................................... 117

11.3 Using the Extensometer Calibration ............................................................................................................. 118

HW Synchronization ........................................................................................................................................... 120

12.1 Introduction .................................................................................................................................................. 120

12.2 Camera Synchronization Panel ..................................................................................................................... 120

12.2.1 Camera Synchronization Modes ............................................................................................................... 120

12.2.2 Additional Synchronization Settings ......................................................................................................... 121

12.3 Synchronization Box – Vibrography Applications ......................................................................................... 123

12.3.1 Connection of the Synchronization Box .................................................................................................... 124

High-Speed Camera Measurement ..................................................................................................................... 125

13.1 Connection of the High-Speed Camera ......................................................................................................... 125

13.2 Operating the High-Speed Camera ............................................................................................................... 127

Custom Series .................................................................................................................................................... 129

14.1 Overview ....................................................................................................................................................... 129

14.2 Configuration Workflow ................................................................................................................................ 129

14.2.1 Expression Editor Access........................................................................................................................... 129

14.2.2 Adding a New Expression.......................................................................................................................... 129

14.2.3 Activating an Existing Expression .............................................................................................................. 131

14.2.4 Importing an Expression ........................................................................................................................... 131

14.2.5 Removing an Existing Expression .............................................................................................................. 131

14.3 Syntax ............................................................................................................................................................ 131

14.3.1 Naming Convention and Precedence ....................................................................................................... 131

14.3.2 Mathematical Operations ......................................................................................................................... 132

14.3.3 Constants .................................................................................................................................................. 134

14.3.4 Recursion .................................................................................................................................................. 134

14.4 Examples ....................................................................................................................................................... 134

14.5 Expression File Format .................................................................................................................................. 134

14.6 Troubleshooting ............................................................................................................................................ 135

Graph Configurator ............................................................................................................................................ 136



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15.1 Graph Configurator Access............................................................................................................................ 136

15.2 Adding a New Graph ..................................................................................................................................... 137

15.3 Graph Annotations ........................................................................................................................................ 137

15.4 Stress vs. Strain Graph .................................................................................................................................. 138

Appendix A. Mercury RTⓇ LiteView ................................................................................................................... 140

Appendix B. Troubleshooting ............................................................................................................................. 141

Appendix C. Tips and Tricks ................................................................................................................................ 143

Measurement of Poisson’s Ratio ....................................................................................................................... 143

Appendix D. Keyboard Shortcuts ........................................................................................................................ 144

Contact ..................................................................................................................................................................... 145



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Brief Overview

The following is a brief overview of steps, which are usually taken before measuring with Mercury RTⓇ. Note however,

that this is just a quick reference and more detailed information on this topic can be found in another document dedicated

to the delivered hardware (MONET 3D, MEVIX…) or in simple version Getting started, which is recommended to read prior

to this reference handbook. If you miss these documents, please ask your local distributor or directly [email protected].

In the above documents you will find following topics:

1. Installation

2. License activation

3. Camera connection

4. New project creation

5. Adjustment of cameras

6. Synchronization of cameras

7. Calibration of cameras

8. Placement of measuring probes

9. Measurement settings

10. Measurement execution

11. Processing of results




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Main Window

The main window provides a basic project management functionality such as the creation of projects, their loading and

saving, options for import and export, as well as tools for specialized use-cases, settings and help. Primarily, the main

window serves for the visualization of computed data by means of graphs and highlighted fields with numerical values. Its

other important features include the real-time display of measured values on a connected testing machine and controls

handling the starting and stopping of a measurement. As portrayed in Figure 1, the main window is comprised of several

distinct parts.

Figure 1: Main window.

2.1 Menu Bar

The menu bar is located at the top of the main window and contains the following items:

Project – Offers a drop-down menu with New, Load, Save, Save as, Close and Exit options.

o In the New tab, it is available to create either a Real-time Measurement, a Real-time Extensometer

Calibration, to create a project From Existing Images, Existing Video Files, an Existing Project Data

Structure or to create a Testing Machine Controller. A real-time measurement requires one or more

connected cameras, whereas an offline measurement needs previously recorded images or videos. See

the section 2.2 for details.

o Load – Loads a previously configured or recorded project from a specified directory.

o Save – Saves the currently open project. This is also done automatically at several critical points such

as starting or stopping a measurement.

o Save As – Copies the currently open project to a different location. See 2.2.1 for details.

o Close – Closes the currently open project.

Graph Data Panel

Menu Bar

Project Panel

Project Controls

Graphs Panel



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o Reinit Cameras – Discards the information about the currently connected cameras and initializes them

again the same way they are processed at program startup. This can be useful when configuration of

cameras changes or when some of them were in an invalid state during detection.

o Exit – Quits the application.

Import – Imports data into the currently open project. A more detailed description can be found in chapter 4.

Export – Exports a configurable amount of measured and computed data into files of various commonly used

formats such as CSV, HDF5, PDF or STL. Further information can be found in the chapter 5.

Tools – Offers post-processing tools for Vibrography, CAD/FEA and FLC/FLD analyses. An option to Create

LiteView Shortcut is also located here. See chapters 6 and Appendix A for detailed information.

Settings – Contains a drop-down menu with the access to the following sections:

o System – Opens the window for the adjustment of settings applied regardless of project currently open.

See the chapter 7.1 for details.

o Presentation – Opens the window for the adjustment of settings, which are only related to the open

project and set how the computed data are presented in the UI. See the chapter 7.2 for details.

o Computation – Opens the window for the adjustment of settings, which are only related to the open

project and set how the data are computed. See the chapter 7.3 for details.

o Change Password – Opens the window for changing a password.

Help – Offers a drop-down menu with these options:

o Examples – Opens a browser of available examples demonstrating the capabilities of Mercury RTⓇ.See

the chapter 8 for details.

o System Selection Guide – Opens the window for helping to choose the best hardware configuration for

the selected requirements of the measurement.

o Check for Updates – Checks for the latest version of the software.

o Request License – Opens the window for requesting a new license.

o Upgrade License – Allows to load a different license file.

o View Help – Opens the reference handbook (this document) of the Mercury RTⓇ.

o About – The About dialog is shown in Figure 2 and displays the information about the version of the

software and the active license.



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Figure 2: About window.

Disk space status viewer – Situated in the upper-right corner of the main window, where it serves as an indicator

of the disk space at the location of the stored data. Indicates the remaining space, the current data flow and the

time left until there is no space available.

2.2 Project Creation

When preparing a new measurement, a new project needs to be created first. This is done by clicking Project -> New in

the menu bar as seen in Figure 3. From the drop-down menu, choose one of the available options. The project name and

its location are set right afterwards.



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Figure 3: New project creation.

The second dialog offers a choice between the categories Mono Cameras, Stereo Cameras, Stitched Mono Cameras and

Stitched Stereo Cameras, as seen in Figure 4. The scene layouts can be combined as desired, allowing for example a project

with a single stereo and two mono cameras. When creating a project for a real-time measurement or an extensometer

calibration, only the active cameras are available in the corresponding column. If the desired cameras are not visible, an

adjustment needs to be made in System Settings under Active Camera Libraries (see 7.1.1). By dragging the requested

cameras to the right column, they are selected to comprise a layout for a new scene in the created project. The selected

cameras may be deselected by dragging them to the bin in the bottom-right corner.

Figure 4: New Project window of a real-time measurement.



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With regard to creating scenes, it is very important to note, that when using high-speed cameras, it is not possible to mix

them with other kind of cameras in a single scene. Likewise when using thermal cameras, is it only possible to create

scenes with a single thermal camera in mono mode. The messages displayed by the wizard ensure the enforcement of

these constraints.

When multiple cameras are selected for a particular scene, an additional page appears in the wizard (see Figure 5). This

dialog is used for choosing blocking cameras. All blocking cameras run at the FPS of the slowest blocking camera and faster

cameras may drop images if not synchronized. This option is normally used for measurements when all cameras have

similar FPS. Unchecked (non-blocking) cameras do not slow down any other blocking or non-blocking cameras. Images

from slower cameras may be repeated to keep consistency. This option is useful for non-measurement purposes.

Figure 5: Choose blocking cameras page.

Additionally, when a stitched stereo scene is selected, another page appears at the end of the wizard, where the field of

view of these cameras must be specified (see Figure 6). Further information is displayed right on the page itself. Connected

cameras do not have to be of the same arrangement as displayed by the images shown on Figure 6. It is only important

that there should be pairs of neighboring cameras, which share a field of view and may therefore be calibrated together.

The setting of whether the cameras form a Partial or Full Circle is only important to specify in order to determine whether

the last camera is neighboring to the first or not.



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Figure 6: Specify field of view page.

Provided that an offline measurement is required, images, videos or Mercury RTⓇ projects are loaded from a specified

directory. When one of the cases From Existing Images…/From Existing Video files…/From Existing Data Structure… is

chosen, a dialog similar to the one in Figure 4 opens. This dialog contains an additional Browse button, which is used to

browse and select the required images, video files or an existing data structure. Once images, video files or data structures

are selected, new offline cameras are made available and they can be manipulated similarly to online cameras.

Whenever a new project from existing images, video files or data structure is being created, there is another additional

page, which appears as displayed in Figure 7. It allows to specify the acquisition times of imported data by either inputting

the FPS value with which the camera was running or by loading a Mercury RTⓇ project file containing the exact acquisition

times.



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Figure 7: Second dialog, creation of a new project from existing images.

2.2.1 Save As By clicking the Project/Save As button, a dialog window seen in Figure 8 opens, prompting for a name of a new

measurement. The recorded camera images in the open measurement can be reused in the new measurement. In this

instance, the new measurement contains either the relative paths of the reused images (if they are located in the directory

of the project or its subdirectory) or their absolute paths. The first option creates an empty measurement. All probes,

calibrations, coordinate systems and other setup are copied to the new measurement in both cases. The same functionality

is available through Copy Project button marked by plus sign icon in the Projects Panel on the right of the main window.

Figure 8: Copy Project dialog.



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2.3 Project Panel

The project panel is situated on the right of the main window, as seen in Figure 1. It provides the means of control over

the current project as well as the configuration of external devices and such.

2.3.1 Projects This menu in the project panel primarily provides a list of projects associated with the current one due to being located in

the same directory. Clicking on the items of this list switches the currently open project to the selected one. The current

project also shows the number of captured frames, as well as the number of batches, among which these frames are

logically distributed. Figure 9 describes three buttons for advanced project management located below this list. By using

these buttons, projects may be copied, renamed and deleted. To copy a project represents the same functionality as

Project/Save As.

Figure 9: Projects tab in the project panel.

2.3.2 Test. Machine When Testing Machine is enabled, the Test Machine panel represents an option of the panel to control DOLI DoPE driven

testing machines or just display data from analog/digital inputs in the case of an absence of a testing machine. For a

detailed description of the configuration of a test rig and its control, see the chapter 9.

2.3.3 Services

Mercury RTⓇ is capable of receiving commands and sending specified values of measured quantities through various

analog and digital channels. The I/O Services panel handles the creation of I/O services and allows their management. See

chapter 10 for more details.

2.3.4 Cameras Contains a panel for the control over camera synchronization and access to a high-speed recording tool (where applicable).

See chapters 12 and 13 for details.

2.3.5 Sync Box Provides the real-time input of a camera synchronization box if such a device is available. See chapter 12.3 for detailed

information.

Copies the selected project

Renames the selected project

Deletes the selected project

Opens the folder of the project



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Figure 10: Sync Box tab in the project panel.

2.3.6 Point Filtering Enables the filtering of data during computation. The offered filter types are averaging, Gaussian smoothing, batches

averaging and polynomial fitting (linear, quadratic or cubic). Batches averaging means that if data is recorded in batches,

only the individual batches are averaged. The items contained in this panel are the same as the respective parameters in

Computation Settings under Point Filtering (see 7.3.6).

Figure 11: Point Filtering and Value Filtering tabs in the project panel.

2.3.7 Value Filtering Enables the filtering of data after the computation is done. The available functions are average, minimum, maximum,

median and standard deviation. Any number of available values may be selected for filtering with the specified function

and the filter is created by clicking the Accept button below. The settings of a value filter are related to values with given

names, so they are no longer valid when the corresponding probes or series are renamed. The created filters are available

in all projects, but the configuration of which of these are active in a project is saved with the project data. All filters are

disabled in a new project.



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Figure 12: Value Filter Settings dialog.

2.3.8 Extensometer Calibration Enables to perform the correction of calibration by means of inputting values from an external gauge. This panel is only

available in a calibration project. For detailed information, see chapter 11.

2.3.9 Project Notes Enables to insert a custom description of samples and tests associated with the project. This does not have any effect on

the computation, only serves for informational purposes and can also be included in generated reports.

2.4 Project Controls

The panel of project controls seen in Figure 13 provides the most necessary controls for data acquisition, performing

computations with these data and browsing recorded data.

Figure 13: Panel of project controls with already recorded and computed data.

The controls are explained as follows:

Project Seeker (Figure 14) – Seeks in the recorded data. Changing the position of the current frame updates the

image(s) displayed in the camera view(s) and causes the highlighting of measured values in graphs. The positions

of the reference frame and the end frame are shown as vertical lines with arrow pointers. The green range shows

the amount of the computed data. The yellow range (not displayed in the picture) means that some of the frames

were not computed although they are written to disk. The light-blue range, which may be overlapping with the

green range, also specifies the range of frames for recomputation, the recording of video files (available through

the corresponding control in the camera view controls of the scene window, see 3.1) and vibrography analysis

(see 6).



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Figure 14: The project seeker.

Seek to Reference – Moves the seek slider to the position of the reference image(s) and displays it/them in the

corresponding camera view(s). Pressing this button once again will instead move the slider to the position of the

last displayed image(s).

Recorded Data Player (Figure 15) – Plays the recorded data in different ways:

o Backplay / Pause – Plays the recorded data backwards or pauses playing at the current frame.

o Play / Pause – Plays the recorded data forwards or pauses playing at the current frame.

o Stop – Stops playing and steps to the reference frame.

o Loop – Enables / disables looping during play. There are two kinds of a loop – circle and bidirectional.

The circle loop continues playing by the reference frame when the end frame is reached. The

bidirectional loop switches direction from forwards to backwards when the end frame is reached and

vice versa when the reference frame is reached.

o Previous Frame – Steps to the previous frame.

o Next Frame – Steps to the next frame.

Figure 15: The recorded data player. From the left to the right: loop, backplay, play, stop, previous frame and next frame.

Set as Reference – Sets the currently displayed frame(s) determined by the current position of the seek slider as

reference. If there are any computed data present, they will be erased on a prompt. A copy of the probes from

the previous reference frame is used in the new one.

Set as End – Sets the current position of the seek slider as the effective end of the record, the same way it would

be set by moving the corresponding element of the seeker by mouse.

Set Mark – Determines the moment in time with data, which serve as an input to various operations such as FEA

and FLC analysis.

Run / Stop – Launches or stops a new test, during which the recording of frames from the connected cameras

takes place, as well as the recording of measured data from the connected test rig and the computation of data

for display in graphs. It is not possible to append new frames to the existing measurements, so a permission to

clear all recorded data is requested on consecutive presses of the Run button. The arrow on the right of the

button opens a context menu with alternate modes of running a new test:

o Run with Timer – Records data in batches of a length specified by the number of frames. The time

between consecutive batches is also specified by the respective numeric control.

o Run in Snap Mode – In this mode, frames are not processed automatically as they arrive from the

connected cameras, but only when the Snap Frame(s) button is pressed. It appears to the right of the

Run button when this option is selected. The data recorded this way is logically stored within batches,

whose length is specified by the respective numeric control.

o Run without Recording – The results are computed without saving both images and measured data

altogether. This means, that the memory demands are kept to minimum and as soon as the test is over,

the project is in the same state as it was before the test.

End frame Current frame Reference frame



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Frames Saved – Toggles the option to save the recorded images into the directory with project files. If disabled,

it will not be possible to view the processed images after the test is stopped. This option is enabled by default.

Saving interval [frames] – Restricts the amount of frames, which are saved to drive during a live test. Specifies

the interval between frames, which are saved and the rest will not be available to further recomputation.

Data Computed – Toggles the option to compute data during a live test in addition to recording the frames. If

unchecked, data are not computed which is frequently used with a checked Frames Saved. In that case, data

can be recomputed later, e.g. when measuring with high framerate. This option is enabled by default.

Initialize Only – Toggles the option to wait until the system is ready for measurement after starting the test by

using the Run button instead of proceeding with the entire measurement. The actual measurement begins only

after the Ready button is pressed, which appears right next to Run. This helps to prevent gaps of not computed

data from forming at the beginning of the measurement due to more computationally expensive operations,

which happen with reference frames. Especially in stereo scenes, because the points need to be correlated

between neighboring cameras first.

Unlock reference – Unlocks the modification of probes in the reference frame, which is locked whenever a

new test or recomputation is started. Some other controls such as Computation Settings (see 7.3) are affected

by this as well. Mind that this operation deletes all computed data.

Recompute / Stop – Performs new computations using the recorded frames, beginning by the frame set as

reference and stopping either on request or when it reaches the frame set as the end of the record. It is therefore

possible to have the computation proceed in either the forward direction or backwards, as determined by the

relative position of the reference frame and the end frame. The difference is indicated in Figure 16. Please note

that it is not possible to perform this action if saving frames was disabled during the live test. The Recompute

button may be switched to a Post-Process button. When using this option, the coordinate system is allowed to

be modified without unlocking reference, yet having the project be recomputed quickly without any correlation.

a)

b)

Figure 16: a) Forward and b) backward recomputation.

2.5 Graphs Panel

Displays a selection of graphs for the computed quantities, which are distributed among their corresponding tabs according

to the units in which they are measured. By default, there are graphs available for all kinds of units used through the

program, with some of them, such as the units of millimeters, being separated between absolute and relative quantities

for a better chance of comparison.



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Figure 17: Graph with shown markers and an open context menu with additional options.

A graph shows the values evaluated by using the selected probes of each camera. The graph panel has several tabs with

different graphs according to various measured units. A graph can be zoomed in by using the mouse wheel or fit to window

by using the double click of the left mouse button. Also notice the possibility of zooming along either the vertical or the

horizontal direction only (scroll on the individual axes). The visibility of each series can be changed by the corresponding

control in the Graph Data panel on the left of the graphs panel.

The basic graph options can be modified using the context menu seen in Figure 17. The first available options are Copy to

Clipboard and Save Image as, which assist with the creation of reports about the results of the measurement. Additionally,

the Configure Custom Series and Graph Configurator options open the windows described in chapter 14 and 15

respectively. Finally, the appearance of the graph can be adjusted by the options Graph type, Graph annotations and Show

markers. The possibility of a manual adjustment of the x-axis and y-axis scale is provided through the Adjust Range of Axes

option and shown in Figure 18. Additional options are available in Presentation Settings under Graph (see 7.2.1).

Figure 18: Manual adjustment of the x-axis and y-axis scale.



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2.6 Graph Data Panel

This panel includes all data values available in the current project for display in graphs and output through I/O services.

Their order in this panel is preserved when sending all values to outputs, which support such feature. The color of the

boxes represents the origin of these values and can be one of the following. Green are values computed using probes and

other measuring tools set in the camera displays. Orange are values measured by connected devices such as test rig, sync

box and cameras for timestamp retrieval (replaced by system time if not available). Red are values computed by custom

expressions. Blue are values computed by value filtering.

As seen in Figure 19, every box has three buttons on the right side. The button right next to the name of the data value

( ) can be used to change the name of the data value to a desired alias, which can be consequently used to input more

straightforward custom series and such. Another button ( ) hides or shows the corresponding data in the graph and the

last button ( ) contains the settings of visual alarms for each of the displayed values and is also used to set the output of

the value through the configured I/O services. For further information on I/O services, see 10.2.

Figure 19: The Graph Data panel.

2.6.1 Visual Alarm In the Visual Alarm tab of the Graph Data Settings dialog, it is possible to configure the boxes of the graph data display to

be colored differently in specified key moments. This helps recognize the critical values even from a bigger physical distance

of the user from the display. The specific parameters are defined as following:

Alarm Enabled – Specifies whether the visual alarm is applied to the associated graph data series.

Normal Value Color – The coloring of the corresponding display when the value is in its normal state.

Alarming Value Threshold – The value of threshold, when the associated graph data value is considered

alarming. Must be different than the value of critical threshold, because their relation to each other determines

whether the associated graph data value is expected to be ascending or descending towards the critical value.

Alarming Value Color – The coloring of the corresponding display when the value is in its alarming state.

Critical Value Threshold – The value of threshold, when the associated graph data value is considered critical.

Must be different than the value of alarming threshold, because their relation to each other determines whether

the associated graph data value is expected to be ascending or descending towards the critical value.

Critical Value Color – The coloring of the corresponding display when the value is in its critical state.



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Figure 20: The Graph Data Settings dialog showing the parameters of Visual Alarms.



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Scene Window

The functionality of the scene window includes the preview of frames acquired by a live camera and the adjustment of its

parameters, the display of imported or recorded images and the setup of tracking probes and the coordinate system, as

well as the calibration of camera distortions. As shown in Figure 21, the scene window consists of the camera view controls

on the left side, the camera view in the middle and the control panel on the right side of the scene window.

Figure 21: Scene window (mono scene mode).

It is allowed to organize the camera views in order to make a measurement or the processing of results clearly arranged

and clutter-free. As displayed in Figure 22, the individual scenes are docked in the desired places by drag-and drop to a

specific position of the cross in the center of the scene window.

Camera View

Control Panel Camera View Controls



26

Figure 22: The dockable window layout.

3.1 Camera View Controls

The controls which affect the camera view of the associated scene window are grouped together in the vertical panel on

the left of the window and are as follows:

Show or hide coordinate system – Shows or hides the coordinate system. In a stereo scene, this is only

available after a custom coordinate system is enabled.

Show or hide metrology tool – Shows or hides the metrology tool. It is only available in a 2D scene. This tool

can be used to visually determine the physical distances within the scene. Its properties are defined by the

currently set coordinate system and some additional parameters located in Presentation Settings under

Metrology tool as described in chapter 7.2.3.

Fit to window – Fits the currently displayed image (camera frame) into the camera view. Zooming in disables

this feature.

Zoom one-to-one – Sets the zoom to 100%, meaning that a pixel of the screen corresponds to a pixel of the

image.

Invert colors (shortcut: I) – Inverts the colors of the displayed image. This feature does not affect the

measured data.

Show Clippings and Histogram – Clippings mark the overexposed/underexposed areas with a red/blue color

as shown in Figure 23. Both overexposed and underexposed areas of the image cause loss of information and

are therefore unsuitable for forming places upon which the measurements take place. The button also displays

a histogram which is not shown in the figure below.



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a)

b)

Figure 23: The coloring of a) overexposed areas, b) underexposed areas.

Pseudo Colors – Converts a greyscale image to a color image for more visual contrast. This does not affect

the computed data in any way.

Flip Image Horizontally – Flips the currently displayed image around its vertical axis.

Flip Image Vertically – Flips the currently displayed image around its horizontal axis.

Rotate Image Left – Rotates the currently displayed image counter-clockwise by 90°.

Rotate Image Right – Rotates the currently displayed image clockwise by 90°.

Hide Labels – Hides labels from the camera view. This is suitable when they overlap too much, slow down

the program or are undesired to be visible in captured screenshots.

Hide Probes - Hides all probes in the camera view. Can be helpful when they obscure the underlying image

too much.

Caliper Tool – Measures distances on the image in the space defined by the active camera calibration and

coordinate system. This function is also available on any of the recorded images even when the reference frame

is locked. In a stereo mode, it however requires the cameras to be calibrated first and the endpoints need to be

found in both cameras.



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Figure 24: Caliper Tool functionality.

Focus Tool – Highlights places with green in the image which are sufficiently sharp to provide information as

a template for correlation.

Figure 25: Focus Tool functionality.

Grid Tool – Toggles the display of four perpendicular lines to help with the alignment of the specimen.

Figure 26: Grid Tool functionality.

Copy Camera View to Clipboard (shortcut: Ctrl + C) – Copies the currently displayed contents of the camera

view to the clipboard. This includes the visible part of the displayed image as well as all other displayed

components.

Save Image – Saves the image into the selected directory.


http://slovnik.seznam.cz/en-cz/?q=perpendicular


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Save Video Sequence – Saves the recorded sequence of images into an AVI file. An additional dialog window

shown in Figure 27 is consequently opened for setting the parameters of the saved subsequence.

Figure 27: Save Video Sequence dialog window.

The path to the output video file can be selected in the topmost control. The Start and End marks of the

subsequence are available under the included seeker – the movement of the two markers selects the

desired range on the time scale. The slider just defines the current image displayed in the camera view window

and has no effect on the resulting output. Its current position can be either Set as Start or Set as End for

convenience. The Format can be set as either YUV 420 or Motion JPEG. The FPS value defines the exported speed

of the video sequence in units of frames per second. Step between frames selects every n-th frame from the

selected subsequence for capture. The Length value shows the expected length of the saved video file as

specified by the other parameters in this dialog. Changing this value automatically adjusts the FPS value to match

the desired length. Two additional check boxes Record only computed frames and Record backwards can be

used to further specify which frames are saved and in which order.

Clip background in saved images – Can be toggled to automatically clip the gray background around the

displayed frame when saving it to an image or video file. Beware as it might clip a part of text and/or color scale

as well.

3.2 Control Panel

The panel is located on the right of the scene window and provides configuration of the associated camera(s), scene-

related settings as well as input of tracking probes, all of which is associated with the current project.

3.2.1 Live Camera This panel provides control over the parameters of the camera and is accessible only when a live camera is present. The

individual controls located in this panel are available only if the connected camera supports their associated features and

some of them may be available only if the associated camera is stopped. They are explained as follows:

Run/Stop Camera – Runs/stops all live cameras associated with the current project. The background color of

this button also indicates whether they are currently running or not. Additionally, along with the FPS value, this

is the only control in this panel, which is available even during a measurement.



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Turn Light(s) On/Off – This button makes it possible to switch the connected light on/off, which is also done

automatically when a test is started or stopped. A precondition to this, however, is that a specific USB relay and

lights must be connected to the computer and its parameters need to be specified correctly in System Settings

under USB Relay (see 7.1.5).

Shutter [ms] – Adjusts the shutter speed of the associated camera. The higher the value, the brighter the image,

but more prone to motion blur. Recommended shutter values for typical measurements are up to 20 ms

depending on the amount of applied light and motion conditions.

Auto Shutter – Toggles the option to adjust the value of the shutter automatically by analyzing the incoming

images. This also makes it possible to adjust the value of the shutter even during a measurement, which is

otherwise denied. In combination with the Auto Function AOI (area of interest) mentioned later in this list, it is

possible to restrict the auto shutter to a specified rectangle in the image.

Gain – Adjusts the sensor gain of the associated camera. The units in which it is specified differ from camera to

camera, with the most common being a unit of dB.

Auto Gain – See Auto Shutter, except it adjusts the value of the gain instead of the shutter. The Auto Function

AOI (area of interest) mentioned later in this list works together with the Auto Gain functionality as well.

Figure 28: The panel with live camera settings.

FPS – Adjusts the frame rate of the associated camera in units of frames per second. This is the only parameter

in this panel, which is allowed to change during the measurement. The change is however not immediate,

because the camera needs to be stopped before the FPS is changed and the started again.

High SNR – Adjusts the number of consecutive frames which are taken as an input to optical data averaging. The

output of such averaging is a single frame with a reduced amount of noise, which is then received instead of the

original, unprocessed frames. The use of this feature decreases real FPS.

Advanced – Opens a window of advanced camera properties depending on the type of the associated camera.

AOI Width/Height – Adjusts the size of the AOI (area of interest). In most cameras, decreasing the AOI increases

the maximum allowed frame rate.

Select Image/Auto Function AOI – Activates/applies the AOI selection in the associated camera. According to

the selection toggled by the arrow on the right of the button, the selected AOI is then applied either to the entire

image or just for the purposes of Auto Shutter and Auto Gain functions. The selection is performed either by



31

manual adjustment of the associated values or by moving the green border lines by mouse. The adjustment of

the top-left corner of the AOI can only be done by dragging these lines. Activating the AOI selection also resets

the maximum frame resolution.

3.2.2 Thermal Camera Whenever a scene with a thermal camera is displayed, a panel for the adjustment of its properties shown in Figure 29

becomes available separately below the more generic Live Camera panel. Most of its controls are related to the calibration

of the thermal sensor itself, but these are only available if the connected thermal camera supports this type of access to

its parameters.

Figure 29: The panel with thermal camera settings.

The controls are described as follows:

Temperature [°C] – The range of temperatures that are mapped to the image data, which are retrieved from the

camera. In units of degrees Celsius. This parameter is always available when using thermal cameras.

Emissivity – The emissivity of the observed object.

Ambient Temperature [°C] – The temperature of the environment surrounding the observed object in units of

degrees Celsius.

Transmittance – The transmittance of the intermediate atmosphere.

Air Temperature [°C] – The temperature of the intermediate atmosphere in units of degrees Celsius.

Load Calibration File – Loads an IR camera calibration file that corrects the measured temperatures. Its current

status is displayed in the box located above the button.

3.2.3 Scene Setup Provides the means of the calibration of the system, definition of the coordinate system and other options. Its content is

different according to whether the scene is 2D or 3D.

3.2.3.1 Mono Scene Setup

The panel depicted in Figure 30 contains controls for the camera calibration and the definition of the coordinate system in

a mono mode. All of the included operations are only optional, yet necessary to maintain a high precision of the performed

measurements.



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Figure 30: Mono Scene Setup tab.

The explanations of the included controls are as follows:

Camera Calibration – Opens a window for the calibration of the associated camera (see 3.2.4).

Coordinate System – Opens a window for the configuration of the coordinate system (see 3.2.5.1).

Show Distortions [px] – Shows a color map, which illustrates the magnitude of the calibrated distortions caused

by the curvature of the used lens.

Load Extensometer Calibration – Allows to load a file containing an extensometer calibration, which was

previously created in a specialized project (see 11).

In addition to the previous options, right-clicking the coordinate system opens the context menu seen in Figure 31. This

contains options like Distance [mm]. The distance (between two known points on the measuring plane in the scene) may

be set this way instead of a calibration. However, keep in mind that proper calibration with the use of a calibration grid is

always more precise than this. Another function of the context menu is Free Edit, which further allows to adjust the

coordinate system manually (without a calibration grid) either in a plane perpendicular to camera or in a perspective view.

The position of the coordinate system may be also locked by Lock Position, which is also done automatically when the

coordinate system is set by detecting the points of a calibration grid or when performing a measurement.

Figure 31: The context menu of the coordinate system in a mono scene.

3.2.3.2 Stereo Scene Setup

The panel shown in Figure 32 replaces the previously described Mono Scene Setup panel in a stereo mode. Unlike the

camera calibration in a mono mode, the calibration of a stereo camera pair is necessary before performing any

measurements. The definition of an optional custom 3D coordinate system is only allowed after the associated stereo pair

is successfully calibrated. The controls in this panel are as follows:

Figure 32: Stereo Scene Setup tab.



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Stereo Camera Calibration – Opens a window for the calibration of the associated stereo pair (see 3.2.4).

Large Object Calibration – Opens a tool for the calibration of large objects (see 3.2.6.3)

Custom Coordinate System – Activates the use of a custom 3D coordinate system (see 3.2.5.2).

Motion Removal – Toggles the computation of displacement for the points of a custom coordinate system.

Measured data is then computed relatively to the displaced coordinate system, effectively making the data

unaffected by the motion (and rotation) of the object, on which the points of custom coordinate system are

positioned. This feature is available only if such a custom coordinate system is active.

Detect in Grid – Sets the position and the rotation of the coordinate system using a calibration grid. The

parameters of the calibration grid are requested first when the button is pressed. This feature is available only

when a custom 3D coordinate system is active. Using this feature automatically locks the coordinate system, so

it cannot be manipulated any further until the lock is disabled in the context menu of the coordinate system.

Load Extensometer Calibration – Allows to load a file containing an extensometer calibration, which was

previously created in a specialized project (see 11).

3.2.3.3 Stitched Mono Scene Setup

The panel represented in Figure 30 is also available in a stitched mono scene. Only the windows opened by the buttons

located in this panel differ, with the camera calibration being done individually for two or more cameras and the definition

of the coordinate system performed in all cameras at once. Also, unlike the plain mono scene, these steps are necessary

to do before a measurement can provide any meaningful results, because the spatial relationship between the stitched

cameras is unknown until then.

3.2.3.4 Stitched Stereo Scene Setup

The Scene Setup panel available in a stitched stereo scene is a reduced version of the panel displayed in Figure 32. In only

contains the Camera Calibration and the Extensometer Calibration buttons. Their function, however, remains the same

as in the case of Stereo Scene Setup.

3.2.4 Camera Calibration The Camera Calibration window is used for the calibration of the distortions of camera lens as well as the geometry of

stereo camera pairs or chains of cameras in stereo with stitching. Please note that some features require or depend on

camera calibration, therefore it is recommended to perform this calibration as the first step after opening the scene

window. Additionally, although it is necessary perform the calibration at full resolution, it is still possible to change the

calibration after the AOI is applied, but the new calibration needs to be already prepared as a separate file.

To start a new camera calibration, click on the Start New button, which is highlighted in Figure 33. A dialog window

appears, containing the Calibration Grid parameters described in chapter 7.3.3. From here, it is possible to select the grid

type, the detection method (either faster or more accurate), the number of radial distortion coefficients and input the unit

distance of the calibration grid. Detect from QR function can be used in case of a circle grid. When the OK button is clicked,

the calibration is ready to start.



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Figure 33: Start new camera calibration.

Camera calibration step-by-step (Figure 34):

1. With respect to Figure 35, capture (Camera Image button) between 15 and 30 images. Pay attention to

avoid over/underexposed and blurry images. The more space of the image is covered by the grid, the higher

the quality of the resulting calibration.

2. Click Compute.

3. Verify if there are some significantly higher error values than others.

4. If so, uncheck these higher error values and proceed with step 5. If not, click Apply.

5. Unchecked images are excluded from the calibration.

6. Click Compute again.

7. Verify similarity of error values again.

8. If all the error values are similar and the average reprojection error is lower than 0.5 (sometimes the

average reprojection error may reach almost 0.8), click Apply. At this moment, the calibration is done. If

not, click Start New to clear all detected calibration grids (except for their corresponding locally stored

image files) and start again.

9. The newly active calibration is indicated by the green status box at the bottom of the scene window. (shown

below)



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Figure 34: Camera calibration step-by-step.

Each camera lens has its specific distortion, which negatively influences the measurement. In this case, it is necessary to

perform a calibration to calculate this distortion so it can be removed later. Camera calibration is performed using a

calibration grid. This grid is captured in various positions and angles in the entire field of view (Figure 35). The quality of

camera calibration increases as more space is covered. Calibration instructions specific for different types of scenes are

given in following four sections.

The other features of this window include:

Load File – Loads a camera calibration from a file. Can be used to load a camera calibration from a different

project.

Save File – Saves the computed camera calibration to an XML file.



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Figure 35: Stereo scene calibration - correct capturing of the calibration grid (turning in different angles).

3.2.4.1 Mono Scene Calibration

Take number of pictures of calibration grid in various positions and orientations but keep calibration grid in the plane of

the measured motion or deformation. Consider that reconstruction of the scene recorded by single camera is highly

sensitive to out-of-plane motion (i.e. motion along the line of sight of the camera) and this so called mono scene setup is

not suitable for measurements that include significant out-of-plane motion or deformation. Stereo setup should be used

in such case. This calibration determines only local distortions caused by camera lens imperfections. The second step

calibrating real distances in recorded scene is described in Mono Coordinate System section 3.2.5.1 later in this handbook.

3.2.4.1 Stitched Mono Scene Calibration

Calibration of stitched mono scene camera setup is performed for distortion of every camera separately and so all

considerations from Mono Scene Calibration section above holds. In addition, every single camera must see only one

calibration grid during every frame capture. Calibration of real distances in XY plane and definition of common coordinate



37

system for the combined stitched scene is then done in following step described in Stitched Mono Coordinate System

section 3.2.5.3 later in this handbook.

3.2.4.1 Stereo Scene Calibration

Stereo scene calibration process provides both all single cameras parameters calibration, camera relative

position/orientation calibration and coordinate system definition. Unlike the mono scene setup, stereo scene setup is not

sensitive to out-of-plane motion as it provides full 3D scene reconstruction and thus stereo scene calibration should be

done with broad range of grid orientation relative to all axes in 3D. Both cameras should have full view of the pattern on

the calibration grid at the same time. Stereo scene calibration window helps with this by reporting whether calibration

algorithm managed to detect the grid with both cameras. For the best precision of calibration, keep the center of

calibration grid in expected position of a measured object.

3.2.4.2 Stitched Stereo Scene Calibration

Stitched stereo scene calibration is similar to stereo scene calibration, except that the calibration images have to be

recorded in such way that the algorithm is able to stitch the full 3D scene together. This is achieved by recording the

calibration grid in a way that each two neighboring cameras see the entire grid at some point during the calibration process.

For example, if four cameras (1, 2, 3 and 4) are connected, several frames should be recorded, where at least cameras 1

and 2 see the full calibration grid and the same needs to be done for cameras 2 and 3 and cameras 3 and 4 (and also 4 and

1 when cameras form a full circle around the measured object). Again, the calibration tool of Mercury RTⓇ reports whether

the calibration grid is detected by the calibration algorithm. It is better to provide an image where more cameras see the

full calibration pattern, but it is not strictly necessary. Several images should be provided for every pair of neighboring

cameras in the stitched chain.

3.2.5 Coordinate System Definition

The coordinate system is a tool for the conversion of computed values into physical units (mm). In a mono mode, the

coordinate system is set independently to the camera calibration, but in a stereo mode, the coordinate system is already

a part of the calibration of the stereo camera pair or chain (stitching). However, even in a stereo mode, a custom coordinate

system may be enabled to allow a user-specified location of its origin and the alignment of its axes. Definition of a

coordinate system in each of the different scene types is described below and can be perform regardless of the current

AOI setting.

3.2.5.1 Mono Coordinate System

The Coordinate System window seen in Figure 36 is accessible through the Scene Setup panel in a mono mode and allows

to set the coordinate system using points of image with known location in physical units. The user is provided an option to

mark the key points in a sketch and then set their coordinates in an external software. Adding more points increases the

precision of the coordinate system because the errors of individual points are statistically eliminated. The reference

measuring plane (coordinate system) is set on the front plane of the calibration grid.



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Figure 36: A calibration grid detected in the Coordinate System window.

The controls located in this window are described as follows:

Load – Loads coordinate system points from a specialized CSV file.

Save – Saves coordinate system points to a specialized CSV file. This can be used to enter the coordinates of

these points in an external program such as MS Excel, which allows the coordinate system to be defined only by

a small amount of points with known location in 2D space.

Custom – Loads a custom image to serve as a layout for coordinate system points.

Point – Enables to add new coordinate points by mouse. Selecting the existing points while Shift button is

pressed removes them instead.

Clear All – Clears all coordinate system data.

Plane Offset [mm] – Allows to move the measurement plane in parallel to the reference plane set by a

calibration grid. A negative value means that the measurement plane is moved further from the camera from

the reference plane set by a grid, as indicated by Figure 37. This feature is available only if the associated camera

is calibrated. It is usually used when the calibration grid is positioned on the surface of a measured object. In this

case, the offset is equal to the negative value of the thickness of the calibration grid.



39

Figure 37: The adjustment of the plane offset (in parallel to the reference plane).

Detect – Detects the points of a coordinate system using a calibration grid with parameters set through the

dialog displayed when opening the window.

Refresh Frame(s) and Detect – Reloads the displayed image as the last displayed one from the corresponding

camera view and runs a detection as if pressing the previous button.

When the coordinate system is set as desired, it can be put into use by pressing the Apply button at the bottom of the

window. Oppositely, the Reset to 1:1 button sets the coordinate system to its default values, where 1 pixel = 1 millimeter.

Since the coordinate system is just an optional, yet recommended part of the calibration process in a mono scene, it state

is indicated by the middle box located at the bottom of the scene view shown in Figure 38.

Figure 38: Status indication of the coordinate system in a mono scene.

3.2.5.2 Stereo Coordinate System

In a stereo mode, the coordinate system which handles the conversion of computed values into physical units (mm) is

already a part of the stereo camera calibration. Such a coordinate system is based on the left camera of the pair and has

its center located inside the camera, X-axis going to the right of the camera, Y-axis going to the top of the camera and Z-

axis going away from the camera. For the purposes of aligning the coordinate system with known points located in the

scene instead, a Custom Coordinate System feature is available and accessible through the Scene Setup panel (see Figure

32) once the associated stereo pair has been calibrated.

The visual representation of the custom coordinate system is made to closely resemble the coordinate system used for

measurements in a mono mode and is displayed in Figure 39. The point labeled as “0” sets the origin of the custom

coordinate system, the point labeled “X axis” sets the direction of the X-axis and the point labeled “XY plane” sets the

rotation of the XY-plane around the X-axis. The individual lines may also be decoupled from the origin of the coordinate

system by dragging them instead of the points.

Measurement

plane

Offset + Offset -

Measurement grid



40

Figure 39: The custom coordinate system in a stereo mode.

The custom coordinate system is set properly only when positions of all of its points in the left camera are detected in the

right camera. This is indicated by a light blue color and a displayed location in physical units (mm) next to the “X axis” and

“XY plane” labels. As with tracked probes, the points in right camera may be dragged to their corresponding positions in

order to increase their likelihood of being successfully detected. If the condition of their proper setting is not met, starting

a new test or recomputation is not possible and will result in a warning message. To avoid this, either set the custom

coordinate system properly or disable it in the Scene Setup panel (see Figure 32). Notice that although the custom

coordinate system may be hidden using the corresponding button in camera view controls panel (see 3.1), this does not

disable it nor change the detection status of its points in any way.

3.2.5.3 Stitched Mono Coordinate System

The stitched mono mode is used to extend the field of view when performing a 2D measurement. As opposed to a mono

mode, the probes are allowed to cross between the stitched cameras if there is a proper overlap as illustrated in Figure

42. Usually, the stitched mono mode is useful when testing hyperelastic materials with a very large deformation or when

measuring long specimens.

The process of the adjustment of the coordinate system in a stitched mono scene is largely different from a stereo or a

mono scene. The following requirements are necessary to perform the definition of the coordinate system correctly. First

of all, a special calibration grid for this purpose must be used as illustrated in Figure 40. This calibration grid differs in the

way that it includes two origins of the coordinate system marked with thicker dots. These origins are highlighted in Figure

40 by red rectangles. Keep in mind that each of these individual origins highlighted in red must be seen in its own camera

as illustrated in Figure 40. Ensure that no camera views both origins at the same time. The green and blue rectangles signify

the fields of view of the two cameras. The overlap of the cameras represents another essential thing. This overlap ensures

a smooth crossing of probes between the cameras. The recommended size of the overlap is approximately twice as big as

the size of the correlation template. If the crossing of probes between the cameras is not accounted for, the overlap is not

necessary.



41

Figure 40: The adjustment of the coordinate system in a stitched mono mode with a special calibration grid.

Notice the buttons for switching cameras in the right top corner in Figure 41 (highlighted in orange). Measurement grid

must be detected through the button Refresh Frame(s) And Detect shown in Figure 41 for each camera individually.

Afterwards, as highlighted in red in Figure 40 and in green in Figure 41, it is necessary to specify the location of the origin

of the coordinate system. Specifically, it means to manually enter values of individual coordinates into the boxes below

(origin position). In the most common case, only the ΔX value should be entered as the X-coordinate, leaving the Y-

coordinate at 0. The plus or minus sign depends on the relative positions of the cameras and possibly some individual

requirements of the measurement.

It is highly recommended to compare e.g. a distance between two points in two cameras by a caliper tool with the real

distance in order to make sure about correctness of the calibration. As depicted in Figure 42, an overlap between cameras

is colored yellow.

Figure 41: Coordinate system window in a stitched mono mode.



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Figure 42: Stitched mono mode – two cameras for FOV extension (an overlap between cameras is colored yellow).

3.2.5.1 Stitched Stereo Coordinate System

Similarly to a stereo mode without stitching, the coordinate system which handles the conversion of computed values into

physical units (mm) is already a part of the stitched stereo camera calibration. Such a coordinate system is based on the

first camera in the setup and has its center located inside the camera, X-axis going to the right of the camera, Y-axis going

to the top of the camera and Z-axis going away from the camera. No other coordinate system is available for these types

of scenes.

3.2.6 Large Object Calibration

To calibrate cameras and define a coordinate system when measuring large objects such as entire buildings or bridges is

possible, but requires certain precautions to be taken. In a mono mode, the camera calibration can be done as usual, just

the lens has to be temporarily focused on a shorter distance when capturing a calibration grid. Further steps are described

in the following chapter.

3.2.6.1 Mono Scene



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To define the coordinate system of large objects in a mono scene, click on the Coordinate System button on the right side

of the scene window under Scene Setup. Enter any number into the unit distance box as it will not be necessary. There

are four default points displayed in the window, which is the minimum number for the definition of the coordinate system.

Additional points may be added by clicking the Point button in the upper panel of the window. Move the points to the

positions whose coordinates are known. Save this configuration as a CSV file. Afterwards, open this CSV file (for instance

in Excel) and edit the coordinate values in order to correspond with the real dimensions of the measured structure.

Remember that all known points must be lying on the measured plane. Save the CSV file and load it in the Coordinate

System window. After that, the measured plane and the coordinate system are set. The definition of the coordinate system

already takes the perspective view into consideration.

Figure 43: Large object calibration in a stitched mono scene.

3.2.6.2 Mono Stitched Scene

The definition of a coordinate system for large objects in a mono stitched scene is mostly the same as in a mono scene.

The only difference is that the relationship between the individual cameras needs to be taken into account when entering

the coordinates of points. These can be set in two different ways. The first way is to set both coordinate systems separately

(with a local origin of [0; 0] for each individual local coordinate system) and then offset them by known values filled in

boxes at the bottom left of the window. The second way is to set both coordinate systems according to the absolute

coordinates and avoid entering any offset.

3.2.6.3 Stereo Scene

In order to prepare the calibration of a stereo scene for measuring large objects, several steps must be taken in the

appropriate order. Initially, the stereo scene needs to be opened as two separate mono scenes and an ordinary calibration

of both cameras has to be performed. Both projects must be saved and closed afterwards. After that, create a new project



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containing these two previously open cameras as a single stereo scene. Click on the Large Object Calibration button in the

Scene Setup panel and follow the step-by-step instructions on how to proceed.

The required mono camera calibrations are already done, so select the calibration files by clicking on Load Mono Camera

Calibration below the left and right camera view as depicted in Figure 44. Next, by selecting Add Point in the upper panel,

position four or more points in one camera and modify their placement in the other camera if necessary. Click Specify 3D

positions of probes at the bottom of the window and fill in the table with proper coordinates of the placed points. After

these necessary steps, the stereo calibration for large objects is done.

Figure 44: Large object calibration in stereo scene.



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3.2.7 Probes The Probes panel contains all available tracking probes and other tools. As portrayed in Figure 45, different buttons are

located within this panel for each of the project types, as some probes do not have their equal counterpart in some other

modes. The descriptions and usage of individual probes are provided below.

a) b) c)

Figure 45: Tracking probes for a) a mono, b) a stereo (with and without stitching) and c) a stitched mono mode.

All probes regardless of their type can be manipulated only when the reference frame is displayed in the corresponding

camera view (indicated by either the LIVE or REFERENCE label in the title of the scene window) and this reference frame

is unlocked (indicated by a grayed-out icon of a lock in the camera view controls panel). The manipulation can be

performed in one of the following ways:

Add probes:

o Select a probe type in the Probes panel.

o OR Select the desired probe type by pressing the corresponding keyboard shortcut (see Appendix D).

o Click on a desired position in the corresponding camera view.

o OR Drag and drop to enter a Line Probe, Chain Probe, Polyline Probe or a Force Gauge.

o OPTIONALLY When adding a polygon (Area / PIV Field), left-click its first node (highlighted) to finalize it

and start a new polygon.

o Press Esc button, right-click anywhere or deselect the probe in the Probes panel when finished.

Delete probes:

o Right-click the probe and select Delete from the context menu.

o OR Hold the Shift button and left-click the probe.

o OR Press the Clear All button in the Group Operations panel to delete all probes.

Move probes:

o Drag and drop points or lines to move the probe to a desired location.

o OR Drag and drop the width measurement points to adjust their position.



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o OR Drag and drop one of the nodes of a polyline or a polygon to adjust its shape.

o OR Middle-click and Drag a strain gauge to rotate it.

o OR Hold the Middle mouse button and Drag and drop a neck gauge or a polygon to move it entirely.

Change the properties of probes:

o Right-click the desired probe.

o Select the name of the probe at the top of the context menu to change its name.

o OR Toggle the computation of desired values by selecting their corresponding items in the context

menu. All probes support this feature even when a deformed frame is displayed in the camera view or

the reference frame is locked.

o OR Change a numeric parameter by entering the exact desired value into its box or selecting one of the

standard values from the drop-down menu.

o OR Perform one of the advanced operations supported by the probe by selecting it in the context menu.

The grey area displayed around the reference probes or some of their components represents the area of the correlation

template as set in the corresponding section of the Computation Settings. Usually, it uses the template size from

Correlation in Time (see 7.3.1.1), but in a stereo mode, the template size from Correlation between Stereo Cameras (see

7.3.1.2) is used instead. Additionally, the points for the measurement of width always use the template size from Width

Correlation (see 7.3.2.3). The displayed area may also be colored differently according to the estimated quality of the

underlying template if this feature is enabled in Computation Settings under Correlation (see 7.3.1).

3.2.7.1 Point Probe

Point probes (shown in Figure 46) are represented by a single marker and primarily used to measure the position and the

displacement of the selected point on the surface of the measured specimen. The features of point probes are:

In all modes:

o The computation of positions and displacements.

o The computation of velocities and accelerations.

o The vector visualization of displacements, velocities and accelerations – in the camera view for mono,

in the 3D graph for stereo.

Only in mono and stitched mono:

o The readout of absolute 2D coordinates of the point probe in the reference frame.

o The conversion to rigid plane probes.

o The computation of positions and displacements in polar coordinates.

o The computation of velocities and accelerations in polar coordinates.

Only in mono:

o The computation of the width of the measured specimen. When selected, a width line is displayed

across the point probe.

o The computation of the width of the measured specimen in polar coordinates.



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Figure 46: A point probe (the measurement of the bending displacement of a tree)

3.2.7.2 Thermal Probe

Thermal probes (shown in Figure 47) are only available in a mono mode with a thermal camera and are represented by a

single marker. Their fundamental difference from point probes is, however, that they are not correlated in time, but rather

remain at specific locations in the image through the entire measurement instead. They are used for measuring

temperatures at these places. The shown temperature, as well as the color of the underlying thermal image are therefore

primarily influenced by the temperature range parameter of the Thermal Camera panel (see 3.2.2).

Figure 47: A thermal probe used for temperature readout at specific locations in the image.

3.2.7.3 Rigid Plane Probe

Rigid plane probes (shown in Figure 48) are only available in a mono mode, are represented by a single marker and used

to compute the movement of the coordinate system over time. When one or more rigid plane probes are present during

a measurement, the coordinate system in each deformed frame is moved so that the change in position (in physical units)

of rigid plane probes is minimized. If less than 5 rigid plane probes are used, this minimized change of position is always

equal to zero. For a visualization, the images displayed in the camera view are also transformed, so that the present rigid

plane probes stay always at the same position in relation to the scene window.



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In a stereo mode (without stitching), the functionality of rigid plane probes is replaced by an optional Motion Removal

feature of the Custom Coordinate System as already described in chapter 3.2.5.2.

Figure 48: Rigid plane probes (applied on the stator of a bearing).

3.2.7.4 Line Probe

Line probes (also known as optical extensometers, shown in Figure 49) are represented by a pair of markers connected

by a line and primarily used to measure the distance between two points (the length of the line probe) on the surface of

the measured specimen. The features of line probes are:

In all modes:

o The computation of lengths and their change from the reference length.

o The computation of angles, angular velocity and angular acceleration.

o The computation of values for a stress vs. strain graph (requires a cross-section area to be specified).

o The conversion to point probes, chain probes and polyline probes.


o The computation of lengths in polar coordinates.

o The readout and entry of the exact physical length in the reference frame.

o The fixation of endpoints – disables the correlation of a given endpoint.

o An option to lock the length and rotation to prevent any further changes of relative positions during

adjustment of the probe.

o An option to align the line with the X or Y axis during adjustment of the probe.

Only in mono:

o The computation of the transversal extension and the Poisson’s ratio of the measured specimen. When

selected, a width line is displayed across the line probe.

o The conversion to neck gauges.

o The computation of the width of the measured specimen in polar coordinates.



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Figure 49: A line probe.

3.2.7.5 Chain Probe

Chain probes (shown in Figure 50) are a modification of line probes (see 3.2.7.4), where the line is uniformly divided into

a specific number of segments, which are correlated and utilized to improve the precision of the resulting data and meet

the specific requirements of the measurement. The number of the dividing segments is modified through the context

menu. The main function of the chain probe is to compute data only by using the segment with the highest elongation

(highlighted by a red color). The points, which are not used during the computation at all, are colored gray. This mostly

includes the two endpoints of a chain probe, but even some of the dividing points as well if the original gauge length is too

high to be able to put them into use. In contrast to line probes, chain probes are stripped of the optional width

measurement functionality.

The reference length of all the segments is set explicitly through the context menu. If there are many dividing points, the

measured line may span over more than one segment. It is also allowed to measure a double of the reference length as

well. Mind that unlike polyline probes, chain probes are only suitable to measure movement in a single axis.

Figure 50: A chain probe during measurement.

The features of chain probes are:

In all modes:

o The computation of lengths and elongations.

o The computation of values for a stress vs. strain graph (requires a cross-section area to be specified).

o An option to compute the selected data by averaging all lines of the chain probe until a certain threshold

of elongation in % is reached (specified as Averaging Threshold).

o The conversion to point probes, single line probe (discarding inner points) and polyline probe.

• Only in mono and stitched mono:

o An option to align the line with the X or Y axis.



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3.2.7.6 Polyline Probe

Polyline probes (shown in Figure 51) are similar to chain probes in that they are formed by a line, which is divided by a

specified number of separately correlated points, but their function is different. Whereas a chain probe only takes into

consideration the displacement in a single axis, a polyline probe takes into consideration the deviation of an object from

its own axis, thus is able to measure the total length of a non-straight object after a deformation or to compute the

maximum deflection of a bending cantilever. If desired, a polyline probe can be divided into independent parts, which

function the same way as separate line probes.

Figure 51: A polyline probe.

In all modes:

o The computation of lengths as a total of all segments.

o The computation of elongations across the entire profile.

o The computation of a true strain.

o The computation of the maximum deflection (the largest displacement of a point on the line).

o The computation of the degree of curvature.

o Free edit, an option to move any divider to any position in the scene.

o The conversion to point probes, single line probe (discarding inner points) or chain probe.


o The readout and entry of the exact physical length in the scene.

o The fixation of endpoints – disables the correlation of a given endpoint.

o An option to lock the length and rotation to prevent any further changes before measuring.

o An option to align the line with the X or Y axis.

o The computation of polar coordinates.

3.2.7.7 Force Gauge

The force gauge (shown in Figure 52) is a modification of the line probe (see 3.2.7.4) used for the computation of a

simulated tear force. This simulation works as a transducer, complementing the values measured by a connected test rig

or replacing them if no such machine is present. The resulting force is computed from the extension of the force gauge

over time and a specified stiffness. The stiffness of the force gauge can be modified through its context menu. It is available

in all scene types and the computation of stress and true stress is available as well.



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Figure 52: A force gauge.

3.2.7.8 Point group

The point group (shown in Figure 53) in the extension of a point probe (see 3.2.7.1), which consists of multiple arrow-

shaped markers, whose exact number is determined when putting them into the scene one by another. In the middle of

these points appears another cross-shaped marker. It effectively functions as a point probe of its own, able to compute

most of the values a point probe could as well, with the major difference, that its position is not correlated in time, but

always computed as a spatial average of the surrounding points. This approach is useful to observe the behavior even in

the places of the image, which do not contain a suitable correlation template, or to compute values related to the entire

group of points, such as the changes in the rotation of the measured specimen. The surrounding points are correlated as

usual, but the loss of one of them during computation results in the loss of the averaged point as well, so their total amount

needs to be kept at a reasonable number. If desired, it is also possible to compute each evaluated value independently for

each of the markers, not just the middle one, by toggling the Points Independent option in the context menu.

Figure 53: A point group used to measure a rotating specimen.

3.2.7.9 Neck Gauge

Neck gauges (shown in Figure 54) are available only in a mono mode and are represented by a rectangle divided by a line

across one of its directions and a specified number of cross-sections in the other direction. It is used to detect an emerging

neck during the tensile test, as well as providing an effective tool for computing the Poisson’s ratio and Plastic Strain ratio.

The distance of the cross-section from either of the endpoints of the dividing line can also be computed and set to the

output as desired. The number of cross-sections and optionally even their desired length (Enforced Width) can be set



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through the context menu. Additionally, either endpoint of the dividing line can be fixed in place, making its position in

deformed images remain constant, ignoring any local deformations. There is also an option to compute data independently

in each cross-section. The position of the neck-gauge is automatically locked when any of the width points is moved by

mouse.

Optionally, a neck gauge enables to use anchor points, which means that every single cross-section is attached to a

corresponding longitudinal location of a measured specimen (a point where the cross-section meets the dividing line). In

this case, the templates for the tracking of movement are displayed in the middle of every cross-section, which assists

them to remain at the correct position through the entire measurement. It is recommended to use this feature every time

when there is a necking present as well as a suitable surface pattern of the sample to make the tracking of these points

possible.

Figure 54: A neck gauge with highlighted neck detection.

3.2.7.10 Strain Gauge

Represented by a rectangle, strain gauges (shown in Figure 55) are available only in a mono or a stitched mono mode and

are used for evaluating strain (or deformation) tensors as well as the Poisson’s ratio. The information about the size of the

strain gauge in physical units (mm) is displayed in the reference frame. The size of the rectangle can be set through the

context menu. The vectors indicating the direction and magnitude of Strain E1 and E2 computed in the edges of the

rectangle may be displayed as well, by enabling them in the context menu. In a stereo mode, strain gauges are replaced

by surfaces (see 3.2.7.11).

Figure 55: A strain gauge.

The computation with strain gauges works in the following way. A correlation template is situated in each of the four

corners and in the middle of the strain gauge. The middle point is connected to the pairs of corner points in a way that it

forms four triangles as depicted in Figure 55 on the right. The deformation of the individual triangles is computed as an

affine transformation. The resulting value is the deformation of the middle point averaged across all four triangles.



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3.2.7.11 Surface

Surfaces (shown in Figure 56) are available only in a stereo mode and are primarily used to visualize the spatial relations

between other tracking probes, hence providing additional visual information in the resulting 3D graph (see 3.3). They are

specified as a polygon, which needs to have its nodes positioned on a single plane in order to achieve the intended results,

because a part of the image from the left camera is displayed in 3D graph on a part of this plane enclosed by the polygon.

Another typical use may be to enclose the template of a measured probe by a surface to have it visible in the 3D graph

afterwards. Note, however, that only areas (see 3.2.7.12) may be used to fully reconstruct the shape of the measured

specimen in 3D space and that both surfaces and areas cannot be viewed in the 3D graph at the same time. An additional

optional functionality of surfaces is to evaluate strain (or deformation) tensors, thus effectively replacing strain gauges

(see 3.2.7.10) in a stereo mode.

a)

b)

Figure 56: A surface used for the visualization of spatial relations between four point probes a) during their input in left and right camera of a stereo pair and b) in the 3D graph.

3.2.7.12 Area

Areas (shown in Figure 57) are used for a full-field analysis based on DIC (Digital Image Correlation). The features of areas

are:

In all modes:

o The computation of displacements.

o The computation of strain or deformation tensors. The type of the tensor is specified in Computation

Settings under Full-Field Measurement (see 7.3.4).

o The computation of velocities and accelerations.

o The computation of engineering stress, Von Misses and Tresca stress values. (requires a manual input of

E and Poisson Ratio in the context menu of the area)

o The selection of statistical functions applied to the computed data.

o An option to separate the area to multiple independent sectors, which causes the selected statistical

functions to be applied to each of these separately instead of the entire defined area as whole.



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o The displaying of principal orientations of the computed strains (or deformations), as well as other

vectors for displacement, velocity and acceleration.

o Mesh preview, which is helpful especially when creating the area from point probes as described later

in chapter 3.2.8.

o An option to automatically fill in holes in the mesh caused by loss of points during computation.


o The computation of positions and displacements in polar coordinates.

o The computation of velocities and accelerations in polar coordinates.

Only in stereo:

o The reconstruction of the shape of the measured specimen in 3D space. This can go up to 360° in stereo

with stitching.

A full-field area is specified using one or more blue polygons, which specify the portion of the space to be included in the

analysis (this is where the correlated points are generated) and an arbitrary number of red polygons, which further delimit

spaces within these blue polygons to be excluded from the analysis (where the points are not generated). In scenes with

stitching, these polygons can be defined each in a different camera, thus extending their coverage over multiple camera

views.

The generated points are displayed as yellow dots on the surface of the included area. They are correlated separately, so

the computational load is heavily influenced by their count – the more points there are in a grid, the more time is required

to compute a single deformed frame. The count of the generated points can be adjusted by changing the grid spacing in

the context menu. If desired, there is also an option in the context menu which hides these points in the camera view.

Figure 57: An area comprised of three “included” and two “excluded” polygons.

The measured values are computed for each point of an area and displayed as a colored map, where the values are mapped

to their corresponding colors from the associated color scale as can be seen in Figure 58. Only a single type of computed

values is displayed at a time. Right-clicking an area with computed data allows to choose the displayed value from a drop-

down menu.

Initially, the quantities in graphs represent the average of values computed in the entire area (or whichever other statistical

function is selected), but individual points may be selected for a display in graphs by left-clicking on them when the

measurement is not running. Additionally, individual included areas can be divided into independent sectors, which allows

to compute the statistical data separately for each sector. As for the color scale itself, its placement can be adjusted by

dragging it with the mouse and it can be rotated by the right mouse button. Clicking the control points of a color scale

switches between the local and global minimum and maximum, and dragging those control points sets a custom value. An

exact value of the minimum and maximum can also be specified via the context menu. These settings are then remembered

for further recomputations until the reference is unlocked. Note however, that the initial values are set in respect with the

minimal ranges specified in Presentation Settings under Color Scale (see 7.2.2).



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Figure 58: The strain distribution (strain E1) on specimens with a natural and speckle pattern.

The display of principal orientations of the computed strains (or deformations) is available for Strain E1, E2 and E3. Other

vectors are available for a generic displacement, velocity or acceleration (not those restricted to a single axis). In a mono

and a stitched mono mode, the vectors are displayed in the camera view, while in a stereo mode they are only displayed

in the 3D graph as they are computed in 3D space and a 2D display is not sufficient for their visualization. The display of

principal orientations is disabled by default and can be toggled by selecting the Hide Vectors function in the context menu.

The reconstruction of an area in the 3D space can be seen in Figure 59. This is displayed in the 3D graph and it is more

precise, the more points have been used for the computation. The image data displayed on the resulting shape corresponds

to the image data displayed in the camera view, where the area was specified.

Figure 59: The 3D strain distribution (strain E1) in the 3D graph.



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3.2.7.13 PIV Field

PIV fields (shown in Figure 60) are available only in a mono mode and used for Particle Image Velocimetry. They are

specified as polygons similarly to areas (see 3.2.7.12), with the exception that the points generated within do not represent

points located on the surface of the measured specimen, but locations in the image itself, where changes are to be tracked.

The computed displacements are therefore not cumulative over time, but always related to the preceding frame.

Also, the functions provided by PIV fields are identical to the ones provided by full-field areas, with the only exception that

the computation of tensors in not possible in PIV fields and vectors are always shown for a generic displacement, velocity

and acceleration to indicate their direction and magnitude.

Figure 60: Displacement of points in a PIV field with displayed vectors.

3.2.7.14 Crack Probe (Beta)

Crack probe (shown in Figure 61) is a technological preview of a tool developed for the measurement of the crack

propagation in materials like metals or polymers. Another possibility is to investigate composite materials. These probes

work only in a mono mode without stitching. The crack probe uses a strain measurement on the surface of the specimen

for its evaluation, and therefore a full-field area (see 3.2.7.12) is necessary as well. The conditions for a proper

measurement with the crack probe are as following:

Full-field area should be defined to compute strain on the surface where the crack propagation is expected.

Crack probe must be placed over this area with its origin placed to the point where the crack is expected to

emerge.

It is helpful to use rigid plane probes (see 3.2.7.3) to remove the motion of the surface in the image. As seen in

Figure 61, two or more Rigid Plane Probes are input to remove the rigid body motion in the camera view for a

better detection of the crack.



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Figure 61: Crack probe over a full-field area.

The propagation of the crack is detected only within this area as the position where the computed strain is larger than the

selected threshold. The length of the crack is measured from the fixed origin of the crack probe to the furthest point of the

detected crack area. The angle of the crack growth is determined as an angle between the direction of the reference probe

and the direction defined by the furthest segment of the crack of length specified as Angle Measurement Distance.

Figure 62: The context menu of a crack probe.

Crack probes have the following unique parameters, which are adjustable via their context menu shown in Figure 62:

Detection Method

o Compact Tension – CT is currently the only method of crack detection that defines the crack as an area

where strain exceeds some specified threshold.

Angle Measurement Distance – The length that is used for the definition of the angle of the crack growth. It is

the length of the furthest segment of the crack that defines the direction of crack growth.

Crack Strain Threshold – The sensitivity of the crack detection, i.e. the amount of strain that indicates the

presence of the crack.



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Prevent Shortening – It can happen that the probe will lose the area that has been considered as crack before

and the crack will become shorter. This prevents the tip of the detected crack from moving back and makes it

stay in the last detected position until it starts to grow again.

3.2.8 Group Operations

a) b) c)

Figure 63: Group Operations panels for a) mono (with and without stitching), b) stereo, c) stitched stereo mode.

The Group Operations panel shown in Figure 54 provides a set of operations which manipulate with multiple probes

together as a group. They are as follows:

Pair Probes – Creates an extension line by pairing two point probes as shown in Figure 64. To perform this

operation, press the Pair Probes button and select two point probes by a left-click. In a stitched mono mode, it

is even possible to pair probes between different camera views this way. Notice that this will not create a line if

the total count of extension lines in the corresponding camera view exceeds the licensing limits.

Figure 64: Pairing of probes.

Group Probes – Creates different types of probes listed below by grouping existing point probes together.

o Average – Creates a point group (for evaluating the average position of the probes).



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o Full-field – Creates a full-field area.

o PIV (mono only) – Creates a PIV field.

If there is already an area created this way, it appends the new positions to the ones already present. In order to

revert this operation, select Convert to Points from the context menu of the area.

Specify Probe Coordinates (stereo only) – Opens a dialog window, which allows to manually specify the physical

coordinates of the input probes to form a custom 3D coordinate system. At least four point probes must be

previously placed in the scene to use this feature.

Detect Markers – Performs the detection of markers according to the currently set parameters of Marker

Detection in Computation Settings (see 7.3.5).

Detection Settings – Opens a dialog shown in Figure 65 which provides an access to the adjustment of the

parameters of Marker Detection. These are identical to those found in Computation Settings, so see chapter

7.3.5 for descriptions of specific parameters.

a)

b)

c)

Figure 65: The dialog of marker detection settings showing a) general detection parameters, b) general parameters including those specific for the detection of lines and c) general parameters including those specific for the detection

of edges.

Clear All – Deletes all probes in the scene.

3.2.9 Parameters The panel of parameters depicted in Figure 66 allows the modification of the most used correlation parameters as well as

some parameters related to post-processing of displayed data. All correlation parameters can be modified in Computation

Settings under Correlation (see 7.3.1). The panel is divided into several sections and contains the following:

Incremental Step – Specifies the frame interval of the incremental correlation. If the number -1 is set, an

adaptive (automatic) incremental correlation is performed.

Vector Density – Specifies the amount of vectors to be displayed on full-field areas and PIV fields relatively to

all the computed vectors in the corresponding grid (only every n-th vector is shown in each direction).

Vector Multiplier – Specifies the multiplier applied to all displayed vectors.

Template Size – Specifies the template size. The Automatic template size button located next to it tries to find

the optimum template size for the currently present probes. The two template sizes in a stereo mode are initially

changed together, because it is not necessary to have them differ in usual situations, but changing them in

Computation Settings can override this. It is also possible to completely detach the template size from settings

by using the checkbox below. This sets the size for the respective scene independently from all other scenes and

settings, allowing to set a different template size for each scene in the project.

Correlation Speed – Specifies the correlation speed.



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Transformation Type – Specifies the type of correlated transformation.

a)

b)

c)

Figure 66: The Parameters panel for a) a mono, b) a stereo (with and without stitching) and c) a stitched mono mode.

3.2.10 Seek Panel The small seeker in the Seek panel shown in Figure 67 can be used as an alternative to the seeker in the main window.

Additionally, it is possible to seek to a next/previous frame by pressing the Page Up/Down button.

Figure 67: The Seek panel.

3.3 3D Graph

The 3D graph depicted in Figure 68 is used only in a stereo mode and shows the computed positions of the specified

tracking probes in a 3D space. The 3D graph is available in the panel next to the left and right camera in the top left of the

scene window. The graph supports basic ways of handling – rotate (left mouse button + mouse move), zoom (scroll mouse

wheel or right mouse button + mouse move) and move (middle mouse button + mouse move). Right-click offers a context

menu, which contains the following:

View rotation pivot – Selects either the center of graph or any of the displayed probes as the pivot for view

modifications (rotation, zoom and such).

Lock Rotation Pivot – Locks the rotation pivot to its current location in 3D space, effectively preventing it from

changing when moving to a different recorded frame.

Copy to Clipboard / Save Image as / Save Video Sequence – Saves the displayed contents of the 3D graph to an

image or a video file in the same way as described in 3.1.

Orthographic Projection – Toggles between orthographic and perspective projection.

Invert Colors – Toggles the inversion of displayed colors.

Hide Labels – Hides all text labels from the display.



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Hide Textures – Hides all mapped textures from the display.

Hide Color Map – Hides color map from the displayed full-field area, thus making the underlying texture visible

more clearly.

Hide Color Scale – Hides the color scale associated with a full-field area from the display.

Displayed Value – Selects the value displayed by the color map of a full-field area.

View Surfaces / Areas – Toggles between the display of surfaces and full-field areas if both are present in the

measured scene.

Figure 68: 3D Graph with its associated context menu.



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Import

The importing capabilities of the program are provided by the Import section of the main menu bar shown in Figure 69.

However, if it is desired to load previously recorded images or videos for an offline measurement, such process is

performed via the New Project wizard instead, as already described in 2.2.

Figure 69: The Import section of the main menu bar.

4.1 Externally Measured Data

The data measured outside the program can be imported through the Import Data wizard (see Figure 70) and associated

with the currently open project. Its prerequisites, however, are that the input data are stored in a CSV file and aligned into

one of its columns. The input CSV file, in which the externally measured data are stored, is set through the field labeled

Measured Data CSV File. Next, the number of the column (with 0 being the first one) in which the measured values are

contained, is specified in the corresponding numeric box and the type of these values is selected right next to it from some

of those, which are used within the program and may also be used as a component in a custom series (see 14). Another

note is that the delimiter used in the input CSV file is set to a semi-colon by default and may also be modified. After

confirming the selection, the Measured Data Import Tool window (described in section 4.1.1) is open.

Figure 70: Import Data wizard.

4.1.1 Measured Data Import Tool The Measured Data Import Tool seen in Figure 71 allows any necessary changes of the alignment of the imported

measured values with the values already present in the open project. The window consists of two graphs. The upper graph

shows a series of measured values in the open project. The series can be changed using the selected series control

containing a list of available values in the open project. The lower graph shows the imported data from a CSV file. The

alignment is affected by the location of the red limiters. The selection of the final range can be specified either by Start

and End or Start/End and Sampling Frequency.



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Figure 71: Measured Data Import Tool for setting the alignment of externally measured data.

4.2 Probes from a Project

Allows to import probes from a different project. This assists with the evaluation of a group of measurements, where it is

desired to use exactly the same kind and position of probes. However, it is only allowed if the types of the scenes present

in the currently open project match the scenes in the imported project. The probes that are already present are discarded.

4.3 Settings from a Project

Allows to import the Presentation and Computation Settings from a different project. Unlike importing probes from a

different project, the scenes in these projects do not need to be compatible with each other. Also note, that all of the

parameters are modified during this kind of import, so it is not possible to import only correlation parameters this way or

so.



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Export

This chapter brings an explanation of exporting data from the current project as files for further processing. As seen in

Figure 72, there are multiple options of export.

Figure 72: The Export section of the main menu bar.

5.1 Export Graph Data to CSV and HDF5

The first item called Graph Data requires any recorded data. As seen in Figure 74, it is required to select the target path, a

field separator and a decimal separator. Moreover, only the selected range of the main seeker may be exported if desired.

According to Figure 73, it is possible to select an arbitrary number of available values to save them in a CSV format. The

format of exported data is fully compliant with common spreadsheet editors such as MS Excel.

Figure 73: The selection of the exported data.



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Figure 74: The settings of the export of graph data.

5.2 Export Area Data to CSV and HDF5

The second option Area Data regards only full-field data. In the CSV file, all data from the points in the range selected as

Source Data are included. It is however possible to split the export among several files to make the transitions between

consecutive frames recognizable more clearly. The dialog previously depicted in Figure 74 is not present in this option.

Figure 75: The settings of the exported of area data.



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5.3 Export STL Model

The export of data as an STL Model requires a stereo measurement with computed full-field area and a marked time-slice.

It means that the Set Mark button has to be applied at the desired moment in time. In this option, a window depicted in

Figure 76 opens. Only one parameter is available, to save it as a binary file or not.

Figure 76: The settings of the STL model export.

5.4 Export Project as Local Example

The option to export Project as Local Example is mostly used in order to create examples, but can also be utilized to create

project backups. Because of the need of having data small enough, there are two choices - to convert data format either

to JPEG or PNG format (see Figure 77). Conversion to PNG files makes it slower and size of the package smaller. Conversion

to JPEG files makes size of the package even smaller, but causes data loss. The directory of local examples is open as a first

choice when selecting the target path.

Figure 77: The settings of exporting project as local example.



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5.5 Generate Report

The last available option of export is to Generate Report in the form of a pdf file. Unlike other options, its parameters can

be adjusted in System Settings under Report Generation (see 7.1.7) shown in Figure 78. These consist of the path to an

optional logo shown in the header of the exported file and a specification whether the project notes (see 2.3.9) should be

included in the report as well.

Figure 78: The settings of Report Generation.

Aside from the optional notes, the body of the generated report contains the images of all the charts currently displayed

in the project (see 2.5). These are followed by the screenshots of the camera displays, which show the currently sought

frames along with the computed probes (see 3). This includes the 3D graphs as well in case any are available (see 3.3).

Note that no computed graph data outside the displayed graphs are present in the generated report, so its content does

not overlap with exported graph data.



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Post-Processing

This chapter contains the explanations behind various post-processing utilities found within the program, usually under

the Tools section of the menu bar in the main window.

6.1 Vibrography

The Vibrography tool is used for the analysis of data in the frequency domain.

Figure 79: The Vibrography tool button.

Figure 80: The Vibrography Tool window.

The data for a vibrography analysis is selected using the Selected Series drop-down box in the top-right. By default, the

entire data series are analyzed. After the spectrum analysis is done, a frequency can be selected by using the Frequency

slider. The computed data is shown in the form of several graphs (Amplitude, Phase, Power and Energy), numerical

information found primarily under the Signal Info tab and images for reference and mapping of data to full-field areas.

To analyze only a selected subset, check the Subset box in the bottom-left and adjust the position (the slider next to it)

and the Size of the chosen subset. When hovering over the subset slider, the information about the selected subset (the

start and end time, the excitation frequency, i.e.) is shown. Using subsets can be useful when analyzing data where

frequencies change over time, as seen in Figure 81.



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Figure 81: Result of the spectral analysis performed on different segments in data generated with an increasing frequency.

6.1.1 Amplitude/Phase tab

This tab contains the graphs of amplitude and phase:

Amplitude Graph – Displays the computed amplitude for each frequency. The amplitude axis can be changed to

a logarithmic or decibel scale in the context menu. The frequency axis can be changed to octaves in the context

menu as well, allowing to perform an octave analysis.

Phase Graph – Displays the computed phase for each frequency. The phase axis can be toggled between degrees

and radians in the context menu. The Phase Offset control under the graph allows to move the position of a zero

phase.

At the bottom of the tab, the value of amplitude and phase for the selected frequency is displayed.

6.1.2 Power/Energy tab This tab contains the power and energy spectral density graphs:

Power Spectral Density Graph – Displays the computed power density for each frequency. The frequency axis

can be again changed to octave in the context menu, allowing to perform an octave analysis.

Energy Spectral Density Graph – Displays the computed energy density for each frequency. The frequency axis

can be once again changed to octave in the context menu, allowing to perform an octave analysis.

At the bottom of the tab, the value of power density and energy density for the selected frequency is displayed.

6.1.3 Campbell Diagram A Campbell diagram is used for the assessment of eigenvalues and other dynamical quantities, mostly in rotor dynamics.

The Campbell Diagram tab is only visible when the Subset box in the bottom-left corner is checked (see Figure 82).

Subset size – Defines the size of data in the time domain for the construction of individual vertical lines of the

Campbell diagram.

Subset overlap – It is a measure of the overlap between individual adjacent subsets.

Quantization bin count – Defines the count of quantization bins. It means that data set in the vertical direction

of the Campbell diagram is distributed in the specified number of bins.

Export subset sweep – Performs computations for different positions of a subset with the size specified in the

corresponding control at the bottom of the Vibrography Tool window. The subset is moved between the



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individual computations so that the overlap with its previous position is the one specified in Presentation

Settings under Vibrography (see 7.2.6). A file is created, which contains the range of timestamps delimiting

these subsets and the associated values of frequency, amplitude and phase, where the amplitude is the

maximum among computed values. If the values of excitation frequencies are present among the input data,

they are exported to the output file as well, and the maximum value of amplitude is picked from the frequencies

in the range of these excitation frequencies.

Figure 82: The Campbell Diagram tab in the Vibrography Tool window.

6.1.4 Signal Info This tab contains the information about the analyzed data:

Minimum – The minimum value among the data.

Maximum – The maximum value among the data.

Peak – The maximum displacement from zero among the data.

Peak to peak – The difference between the maximum and the minimum.

Effective value – The effective value of the data (also called root mean square).

Crest factor – The crest factor of the data. The crest factor is a measure of a waveform showing the ratio of peak

values to the average value. In other words, the crest factor indicates how extreme the peaks are in a waveform.

When performing a full-field analysis, the displayed values are averages of the computed values for each point.

Additionally, if the Subset box is checked, improved Signal Info is available. While the Signal Info tab with unchecked

subset shows only one set of signal data for the whole interval, the improved Signal Info provides a specific number of

signal data sets for the individual intervals.



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6.1.5 Preview The preview panel (the images on the right side of the window) contains the computed data at the selected frequency

previewed on the reference image. Both the amplitude and the phase for the selected frequency are displayed. When

previewing data computed for a full-field area, the amplitudes and the phases are computed in the entire area and

displayed using a color map. In the phase preview (bottom), the reference point can be selected by left-clicking the points

of the color map. When the reference point is selected, phases are computed as relative to the phase of this point (the

phase of the reference point will be zero). Otherwise, phases are computed according to the start of the measurement.

6.1.6 Export Some of the data computed as a part of the vibrography analysis are available to be exported into a CSV file and processed

externally in a spreadsheet editor such as MS Excel. This option is performed through the context menu of the graphs of

amplitude and phase. As of now, the data can be exported as follows:

Export Data – Creates a file containing the values of the computed amplitude and phase for each frequency.

Export Subset Sweep – Available via the Campbell diagram tab, see 6.1.3.

6.1.7 Other controls

Display ODS – Opens the Operational Deflection Shape dialog (see Figure 83). This dialog shows a 2D or a 3D

graph of the desired quantity for the frequency selected in the Vibrography Tool window. For a better

visualization in the ODS dialog, change the following parameters:

o Multiplayer – Defines the multiplication rate. The higher this multiplier is, the more significant the

displacements and the deformations are in this window.

o Loop – This box sets the length of the period of the displayed motion in the time domain. The shorter

the loop is, the faster the played motion is.

Settings – Opens a dialog with the most common vibrography settings. All of these settings can be found in

Presentation Settings under Vibrography (see 7.2.6).



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Figure 83: The Operational Deflection Shape dialog.



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6.2 CAD/FEA Validation

The main purpose of the CAD/FEA tool is to perform the validation of externally computed models using full-field data

computed by Mercury RTⓇ. This is for the external models with values obtained through Finite Element Analysis or any

other means. In addition, even the external models of measured objects without any computed values may be used to

compute the difference between the positions of the nodes, which comprise the mesh of the model, and the points of the

full-field area computed in Mercury RTⓇ.

Figure 84: The CAD/FEA tool button.

Please note, that the access to this feature is only available in a project with any stereo camera, which contains full-field

data computed using an area (see 3.2.7.12). Also, the precise moment in time with data, which are to be used for the

validation, has to be marked in the project seeker of the main window using the Set Mark button (see 2.4).

6.2.1 CAD/FEA Tool Window

Figure 85: The CAD/FEA tool window.

At first, the window shown in Figure 85 only contains its own 3D graph display with the full-field data selected in the

previous step. The view is controlled in the same way it is in the 3D Graph of the scene window associated with a stereo

camera (see 3.3). The import of the external model to be displayed alongside the computed 3D area is done by the Import

Model button located at the bottom-left of this window. The detailed function of this button, as well as of the other

buttons located in the bottom part of this window, is described as follows:



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Import Model – Imports an external model from a file with a format of STL, Comma Separated Values (CSV) or

VTK. In the case of a CSV file, a dialog is shown, which prompts to select the columns containing the positions of

the imported nodes and optionally even values associated with them, if such are present in the file. The imported

model is then displayed in the 3D graph display above, alongside the model computed in Mercury RTⓇ. Then

according to whether the imported file contains information about the triangulation of the model as well, it is

displayed either as an interconnected mesh or a point cloud. If the positions of the nodes were imported with

the associated values, they are mapped to the color of either the points in the cloud, or the surface of the model.

Lastly, if only the triangulation is available and the values are not, the surface of the model is not shown by

default, but can be enabled by pressing the button, which appears in the top right corner of the 3D graph display.

This is however not recommended out of performance reasons due to the possibility of the imported model

containing a very large number of triangles, which would have to be displayed all at once.

Compare Geometry – Matches each point of the computed full-field area with the closest node of the imported

model and computes the displacement from the point to the node alongside the surface normal in the position

of that point. The results of this operation are then mapped to the color of the surface of the computed full-field

area and represent a geometry comparison between the computed and imported model. Pressing this button

again restores the display to its original state before the comparison.

Compare Values – Matches each point of the computed full-field area with the closest node of the imported

model and computes the difference between the value associated with that point and the value associated with

the node of the imported model. This functionality is therefore available only if the imported model contains

any externally computed values. Just like following the geometry comparison, the results of this operation are

mapped to the color of the surface of the computed full-field area. Pressing this button again restores the display

to its original state before the comparison.

Export Comparison – Exports the results of the selected comparison into a specified CSV file. The format of the

exported data is fully compliant with common spreadsheet editors such as MS Excel.

6.2.2 Alignment of Models Although it is required for the imported model to be defined in the same coordinate system as the model computed in

Mercury RTⓇ regarding the distances between the points on the surface of the model, the origin points of these two

coordinate systems will be different, which brings the need to perform a manual alignment of these two models. For the

aforementioned purpose, the CAD/FEA tool provides means of manipulating with the placement of the imported model,

specifically by modifying its translation and rotation parameters. These controls are located on the bottom of the window

above the buttons described in the previous section and are comprised of three numeric boxes for translation and three

for rotation – one for each axis. As an addition to these boxes, there is a button next to the controls of the translation

parameters, which aligns the center of the imported model with the center of the computed full-field area. This may serve

as a good starting point for further adjustments. Another button is located next to the controls of the rotation parameters

and its function is to flip the coordinates of the nodes in the imported model along the XY plane.



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6.3 FLC/FLD Analysis

The Forming Limit Curve (/Diagram) analysis is a method used for the purpose of assessing sheet material formability. The

FLC/FLD analysis can be performed only in a stereo mode.

Figure 86: The FLC/FLD tool.

6.3.1 FLC Analysis Process

To get a forming limit curve, the following process is recommended. The higher the number of measurements, the more

reliable results are expected.

Figure 87: Important points when preparing the input data for an FLC analysis.

The forming limit diagram consists of principal strain values at the moment of failure, which is why it is necessary to mark

the moment of failure by the Set Mark button (Figure 87) and save the project. The same process should be done for other

measurements, which must be saved under different names. When all the projects like the previous one are saved in one

directory, then the FLC/FLD tool (see Figure 86) has to be opened. There is also a shortcut called “MercuryRT FlcAnalysis”

installed with the software, which launches the Forming Limit Diagram window seen in Figure 88. Remember that if only

one set of strain values per measurement is required, no path measuring component should be inserted to any project (as

seen in 6.3.2).

The maximum major strain and the corresponding minor strain in the same location are obtained at the moment of failure.

According to the respected standards, a sufficient number of measurements must be realized for each type of specimen.

The individual data sets for each type of specimen should be put in the same group through the button highlighted in red



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in Figure 88. The green points are the average values of the individual specimen groups. The descriptions of these points

can be displayed in the diagram by Ctrl + left mouse click on them. Keep in mind that the acquired data may be exported

to CSV file and required probabilistic analyses can be executed additionally.

Figure 88: The Forming Limit Diagram window.

6.3.2 Area Cross-Sections Graph The specialized area cross-sections graph is mostly used when performing an FLC analysis, but can be applied for other

appropriate full-field analyses as well. After performing any full-field measurement, drag the middle mouse button across

the path you are interested in to insert a path measuring component shown in Figure 89. All the desired courses of strain

values are displayed in the area cross-sections graph. The parameters related to this process can be adjusted in the

Presentation Settings under Post-Processing (see 7.2.5). The relative size of the specimen refers to the ISO 12004-2

standard.



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Figure 89: Path measuring along the component created by dragging the middle mouse button.

Notice a special curve in the graph named “… Curve” which is created in order to fit a corresponding curve by an inverse

parabola concerning the standard mentioned above as depicted in Figure 90.

Figure 90: Area cross sections graph.



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Settings

The following chapter is an overview of settings which can be configured through the settings windows accessible from

the main menu (Figure 91). The individual options are separated into a group of settings applied thorough the entire

application regardless of which project is open (referred to as System Settings) and a group of settings applied only within

the open project (referred to as Presentation and Computation Settings). Next, the options within these groups form

several sub-categories according to which part of the application they are logically associated with. The descriptions of

these options are also available inside the settings window underneath the property grids.

Figure 91: Settings section of the main menu bar.

7.1 System Settings

Figure 92: System Settings window.

The System Settings window contains the group of settings applied through the entire application regardless of which

project is open. They are saved automatically when exiting the application and loaded when it starts.

7.1.1 Active Camera Libraries This section contains the list of active camera libraries. It indicates which camera device libraries should be initialized at

program start-up. Some libraries may take a long time to initialize so this can significantly shorten the boot-up time. The



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most commonly used libraries are enabled by default. Changes in these settings will be applied by reinitializing the

cameras, which is performed automatically if possible and notified upon if not.

When using Ethernet cameras in certain versions of MS Windows, it might not be enough to select the desired cameras

from this list, but it is also necessary to allow the application in the Firewall settings of the operation system!

7.1.1.1 Camera Link

This sub-section contains the global parameters of Camera Link cameras. It is applicable when AVT Camera Link Cameras

or Basler Cameras are active concurrently with Sapera devices.

Camera Config File – The full camera configuration file path of your camera. Please contact Mercury RTⓇ

development team, if no configuration file exists for your camera.

Camera Link COM Port – The COM port parameters used for the communication between AVT cameras and a

frame grabber. They all represent settings of the used COM ports and are as follows: Port Name, Baud Rate,

Parity, Data Bits, Stop Bits and Handshake. Specify an empty string as port name to set the COM port as none.

7.1.2 Cameras This section contains the parameters of live cameras.

7.1.2.1 Slave Camera Trigger

See 12.2.2.1 for detailed information.

7.1.2.2 Master Camera Trigger

See 12.2.2.2 for detailed information.

7.1.2.3 Ethernet Cameras

This sub-section contains the parameters of Ethernet cameras.

Network Packet Size MTU – The size of MTU packet in bytes. For most values to function properly, it is necessary

to have jumbo packets allowed in the settings of the associated network interface.

7.1.2.4 DirectShow Cameras

This sub-section contains the parameters of DirectShow cameras.

Use max resolution – Determines whether to use the maximal camera resolution by default.

Default width/height – The default width/height of camera picture in pixels.

7.1.2.5 IDS Cameras

This subsection contains the parameters of IDS cameras.

Maximum FPS Limit [%] – Specifies the percentage which adjusts the maximum settable FPS of the camera. This

is because using optimal pixel clock together with small AOIs and/or higher exposure times may result in camera-

internal overload, which prevents frames from being transmitted properly. (98% is the recommended value

according to uEye documentation)

Synchronization FPS Limit [%] - Determines the percentage of maximum FPS, to which the camera is set when

externally synchronized (including slave mode). The resulting absolute FPS value needs to be higher than the



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operational FPS value, because otherwise it has been shown to restrict the incoming pulse. On the other hand,

a high FPS value restricts the upper limit of the exposure time, so it is advisable to adjust this value below full

100% as necessary.

Use optimal pixel clock – Specifies whether to automatically detect and set an optimal pixel clock when opening

the camera for the first time (requires restart). Recommended when it is desired to have a small AOI and the

highest possible FPS.

Testing Period [ms] – The time period during which it is unwanted to drop a single frame during the detection

of the optimal pixel clock. Higher values yield more stable results, but the image capture is suspended when the

detection takes place (displaying only white frames or none at all). Must be in the interval of 4s – 20s.

Fallback Pixel Clock [MHz] – The value of pixel clock in MHz which is set to the camera in case an optimal pixel

clock is desired, but its automatic adjustment is not supported by the camera.

7.1.2.6 Camera Display

This sub-section contains the parameters of camera displays.

Default Number of Camera Frames per Second – The system-wide parameter for the default value of camera

FPS.

7.1.2.7 Other

This contains all parameters, which do not have their own sub-section

System Timestamp Correction Enabled – Enables a correction of frame timestamps assigned by the system.

Useful for cases, when it significantly differs from the timestamp provided by camera due to some delay on the

frame acquisition interface. Do NOT use this with hardware synchronization and in other cases, where the frame

rate may vary through a single run of the camera.

Input buffer size for receiving camera frames – Larger values will even-out incoming camera frames, potentially

computing more data. The cost is additional delay. Minimal and default value is 1.

7.1.3 Synchronization Box

See 12.3 for detailed information.

7.1.4 Test Rig This section contains the parameters of a test rig. Changes in these settings will be applied after restarting the program.

Active Test Rig – The type of the currently active test rig for sensor readout and control.

Active Sensors – Indicates whether the corresponding value will be used for all outputs (graphs, displays,

analog/digital outputs...)

Sampling Rate [Hz] – Sampling rate of data recording in Testing Machine Controller projects. It is also used for

sampling rate of SobriECU.

7.1.4.1 Doli EDC

This sub-section contains the parameters of a DOLI DoPE EDC device for sensor readout and control.

Version – The version number of DOLI EDC, DoPENet.dll and DoPE.dll.

Device ID – EDC device number (0-n).

Setup Number – EDC setup number (0-8).



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7.1.4.2 Analog Input

This sub-section contains the parameters of the analog input for sensor readout using MCC and Advantech devices.

Device Number – Number of analog device used for input of sensor data.

Load Channel [N] – Parameters of load channel (with values in units of N). These are the number of the channel

for this analog input, minimal input value and maximal input value.

Extension Channel [mm] – Parameters of extension channel (with values in units of mm). These are the number

of the channel for this analog input, minimal input value and maximal input value.

Position Channel [mm] – Parameters of position channel (with values in units of mm). These are the number of

the channel for this analog input, minimal input value and maximal input value.

Sensor N – Parameters of the channel corresponding to the N-th sensor. These are the number of the channel

for this analog input, minimal input value and maximal input value.

7.1.4.3 Digital / Analog Input COM Port

This sub-section contains parameters of COM port for Digital Input or Tensoamp Analog and Tensoamp Bridge Input. They

all represent settings of the used COM port and are as follows: Port Name, Baud Rate, Parity, Data Bits, Stop Bits and

Handshake. Specify an empty string as port name to set the COM port as none.

7.1.5 USB Relay To connect a USB relay which serves as a device for switching lights (either automatically or manually through the Live

Camera panel, see 3.2.1), the connection parameters must be set in this section.

Connection – The COM port parameters of the connection with device. They all represent settings of the used

COM ports and are as follows: Port Name, Baud Rate, Parity, Data Bits, Stop Bits and Handshake. Specify an

empty string as port name to set the COM port as none.

Switch Output State Delay [ms] – Time how long it takes to switch the output state.

Communication Timeout [ms] – Defines how long the software will wait for a device response.

7.1.6 Remote Presenter This section contains the configuration parameters of remote wireless presenters. Such a remote presenter is a device

used for assistance with the camera calibration (by remote activation of the Capture Image button) and the definition of

coordinate system (by pressing the Refresh and Detect button). It can also be used for the activation of a Snap Frame

button. Either of the configured activation keys may be used for any of the aforementioned functions.

7.1.7 Report Generation

The parameters of report generation.

Header Logo Path – The path of the image to be used as a logo in the header of the report.

Include Project Notes – Specifies whether to include the project notes in the generated report. Only applied

when the template of the notes is modified in any way.

7.1.8 Debugging This section contains the parameters for debugging purposes. The technical support may request a change of some of

these parameters, which should be avoided otherwise.



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7.1.9 Examples This section contains the parameters of the use-case examples.

URL – URL of online examples for downloading.

Examples Local Path – Local path of examples folder.

7.1.10 Application This section contains the parameters of the application interface.

Language – The language of the user interface.

Request Password – Indicates whether to request password prior to allowing the access to the main application

window. Other application entry points such as Lite View are unaffected.

Free Disk Space: Remaining Time for Warning / Fail – When the remaining disk space where the target project

directory is located is less than the Warning / Fail threshold, a warning / failure message is issued to notify the

user that there is only a limited time for recording or that they cannot run a test.

UI Update Frequency [Hz] – Idle – Images and values in the UI are updated with the specified frequency. This is

applicable when a test is not running or data is not recomputed. The allowed range is <1; 50>Hz. Does not affect

data value output to connected systems. The default value is 10Hz.

UI Update Frequency [Hz] – Running – Images and values in the UI are updated with the specified frequency.

This is applicable when a test is running or data is recomputed. The allowed range is <0; 50>H. In very high-speed

tests, 0 can be specified to completely disable UI updates for greater performance. Does not affect data value

output to connected systems. The default value is 2Hz.

7.2 Presentation Settings

The Presentation Settings window is only accessible in an open project. The saving and loading of these settings takes

place altogether with the rest of the project data.



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Figure 93: The Presentation Settings window.

7.2.1 Graph This section contains the parameters of graph displays.

Real–time History Size – Number of points shown in graph during real-time measurement.

High Quality Point Count – Number of points shown in high quality. A large number decreases performance in

large data sets.

Line Thickness – Line thickness of graph series.

Scale number of decimal places – Number of decimal places in scale.

Use superscript exponential format – This format will convert 1.5E+03 to 1.5·10^{3} and render the superscript

properly.

Use exact number of decimal places in scale – Determines whether all scale labels have exactly defined number

of decimal places or maximal number of decimal places.

Poisson’s Ratio Minimal/Maximal Value – The minimal/maximal value of Poisson’s ratio measured for the

current sample that may be displayed. (used to filter out noise during measurement)

Plastic Strain Ratio Minimal/Maximal Value – The same, but for plastic strain ratio.

7.2.2 Color Scale

This section contains the parameters of the color scale associated with full-field areas and PIV fields.

Level Count – The number of levels on the color scale.

Hue Range – The range of hues covered by the colors of the scale. Must be in the interval of (0, 360).

Min Resolution Px – The minimal resolution of the color scale when computing values related to distance.



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Min Resolution Percent – The minimal resolution of the color scale when computing values related to relative

change.

Min Resolution mm in 3D only – The minimal resolution of the color scale when computing values related to

distance in measurements on stereo cameras.

Expressive Line Coloring – Specifies whether to use expressive coloring for line probes and also which scale

resolution to use when mapping the measured value to a color. Applied to polyline probes and trunk gauges as

well.

Reverse Colors – Specifies whether to use the color for maximum instead of the color for minimum and vice

versa. This is applied to any color scale or line coloring, which uses these parameters.

7.2.3 Metrology Tool The parameters of the 2D measurement tool.

Scale Step – The distance between neighboring lines in physical units (mm).

1st/2nd Limiting Line on X/Y axis – The X/Y coordinate in physical units (mm) of the first/second limiting line,

which is perpendicular to the X/Y axis.

Subpixel Mode – Enables the readout of distances using measurement tool (and some of the probes as well)

with subpixel precision. Not available in stereo cameras and not recommended for computation purposes!

7.2.4 Recorded Data Playback This section contains the parameters of the playback of recorded data. They are applied when saving video sequences as

well as during regular playback.

Frame Rate – The speed of playback in frames per second.

Play Only Computed Frames – Indicates whether to skip frames which do not contain any computed data during

playback.

Play Only Saved Frames – Indicates whether to skip missing frames during playback.

7.2.5 Post-Processing

This section contains the parameters of post-processing, mostly related to full-field measuring tools.

Vector Density – Specifies the amount of vectors to be displayed on full-field areas and PIV fields relatively to

all the computed vectors in the corresponding grid (only every n-th vector is shown in each direction).

Vector Multiplier – The factor by which all vectors are multiplied during visualization. This also includes the

vectors associated with point probes, strain gauges and surfaces.

Section Count – The number of sections entered using middle mouse button on an area with computed values.

Section Spacing – The relative spacing between individual sections.

Section Segment Count – The number of segments generated for a single section.

FLC Analysis: Specimen Relative Size – The relative size of the specimen used for the FLC analysis. 1 corresponds

to the size defined by ISO 12004-2.

7.2.6 Vibrography This section contains the parameters of vibrography.

Method – Selects the method of the Discrete Fourier Transformation, by which the spectrum is calculated.

o Single Spectrum – Spectral analysis is calculated in the whole length of the sequence.

o Welch´s Method – Spectral analysis is calculated in parts. All parts are added together and averaged.



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Window Type – Selects the window function that will be used for windowing of data before performing the

spectral analysis. Supported window functions are:

o Rectangular Window

o Hann Window

o Hamming Window

o Tukey Window

o Blackman Window

o Flat Top Window

Data Step – The number of points that is skipped between measurements of spectrum. (Welch’s method only)

Window Size – The size of the window from the entire data that is used to analyze the spectrum at a given time.

Must be even. (Welch’s method only)

Octave Analysis – The parameters of the octave analysis.

o First band nominal frequency [Hz] – The center frequency of the first octave band.

o Last band nominal frequency [Hz] – The maximum allowed frequency for the center of the last octave

band.

o Octave fraction number – The number of created bands between two consecutive main octave bands.

The center frequency of each main octave band is equal to two times the center frequency of the

previous main octave band. For example, the fraction number 3 corresponds to the 1/3-octave analysis.

Lowest Decibel Value – The lowest dB value to be displayed in the graph of amplitude. Must be negative.

7.3 Computation Settings

The Computation Settings window contains parameters applied only within the open project. Their saving and loading

takes place altogether with the rest of the project data.



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Figure 94: Computation settings window.

7.3.1 Correlation This section contains the parameters of correlation.

7.3.1.1 Correlation in Time

This sub-section contains parameters of correlation for a single camera in time domain. The principle by which these

parameters are used to compute data associated with deformed frames is depicted in Figure 95. Parameters of correlation

of width points (see 7.3.2.3) and correlation between left and right camera in stereo camera pairs (see 7.3.1.2) are specified

independently, but consist of the same set of parameters nonetheless.

Figure 95: Principle of correlation in time domain.



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Correlation Loss Guard – Prevents loss of point during correlation by correlating additional points around each

correlated point.

Remove Image Blur – Tries to blur either reference image or a reference image so that they match as close as

possible. Helps when there is difference in focus between images (for example when correlating between left

and right camera).

Speed – Specified base correlation method. Slower methods have greater chance to track larger movements.

Can be set to one of the following options:

o Fastest – Searches small neighborhood.

o Fast – Searches intermediate neighborhood if necessary.

o Normal – Searches whole image for a limited number points if necessary.

o Slow – Searches whole image for all points if necessary.

Maximum iteration count – Maximum number of iterations performed per point.

Maximum square residual per pixel – Maximally allowed average squared error between reference image part

and deformed image part warped using correlated transformation. The value is calculated as average of the

squared difference between values in individual pixels.

Confidence interval – Reliability threshold for 95% confidence interval in pixels. Represents measure of the

correlation quality. For instance, the default value of 0.2 px means that the found point is located within ±0.2 px

within the computed location with the 95 % probability. Smaller values are more discriminating (i.e. fewer points

may be computed with higher reliability).

Correlated transformation type – Specifies parameters that are correlated. The precise meaning of the terms

used in these descriptions can also be found depicted in Figure 96. To avoid problems during computation, the

transformation type should be estimated according to expected movement of measured specimen. Can be set

to one of the following options:

o Omnidirectional translation – Defines displacement in both axes (vertical, horizontal).

o Horizontal translation – Defines horizontal displacement in relation to camera.

o Vertical translation – Defines vertical displacement in relation to camera.

o Omnidirectional scale and translation – Defines either stretch or contraction with combination of

displacement in both axes.

o Horizontal scale and translation – Defines either stretch or contraction in horizontal direction with

combination of horizontal displacement.

o Vertical scale and translation – Defines either stretch or contraction in vertical direction with

combination of vertical displacement.

o Horizontal scale and omnidirectional translation – Defines either stretch or contraction in horizontal

direction with combination of displacement in both axes.

o Vertical scale and omnidirectional translation – Defines either stretch or contraction in vertical direction

with combination of displacement in both axes.

o Full affine transformation – The affine transformation type contains all three types together (translate,

scale and shear). There are 6 calculated parameters. Rotation can be described as well by composition

of shear and scale.


http://slovnik.seznam.cz/en-cz/?q=reliability


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Figure 96: Transformation types.

Correlation Quality – Specifies interpolation method used in correlation. More complex methods are slower.

Template height/width – Height/width of the correlation template (subset) in pixels. These specify the number

of pixels which are used for the correlation template. The size of the template should match the size of the

smallest structures found in the image. Large values are more likely to be found, however take more time and

may not sufficiently represent local deformations. Small template sizes are faster and able to represent local

deformations well, however the lack of image information might result in points not being correlated.

a) b)

Figure 97: Template size and placement – a) the right way to do it, b) the wrong way to do it.

7.3.1.2 Correlation between Stereo Cameras

This sub-section contains the parameters of correlation between cameras in a stereo scene (pair of cameras / stitching).

The principle by which these parameters fit into computation done during measurements using stereo camera pairs is

depicted in Figure 98. They are also applied during input of reference probes through camera displays of these cameras.

In stereo stitching, this concept is just further expanded by each set of two neighboring cameras forming a separate stereo

camera pair. For explanation of these parameters, see 7.3.1.1.



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Figure 98: Principle of stereo pair correlation.

7.3.1.3 Incremental Correlation

This sub-section contains the parameters of incremental correlation. Finding correspondences between the current and

the first frame starts to be impossible when scene changes greatly over time. To solve this problem incremental correlation

can be used. When incremental correlation is used, reference frame is regularly updated. When current frame is being set

as reference frame, correspondences between first and current frame are stored. Calculation of correspondences between

new frame and first frame is done by combining correspondences between first and reference frame and between

reference and new frame. It is desired to change reference frame when as much as possible correspondences are found,

because those not found will not be found in all next frames.

Mode – Determines a mode for the incremental correlation.

o Off – Turns the incremental correlation off.

o Manual – The length of the incremental correlation sequence is set manually by the next parameter.

o Automatic – The reference images are automatically reset when not enough points are computed.

Images between resets – The number of images in correlation sequence after which a reference is reset to a

current image.

7.3.1.4 Stereo Correlation

This sub-section contains the parameters of correlation for a stereo camera in time domain.

Maximum Accepted Triangulation Error – Maximum allowed triangulation error of correlated points. A value of

0 disables calculation of this error.

7.3.1.5 Tensile Tracker

This sub-section contains the parameters of tensile testing tracker, which is utilized by chain probes.

Relative Required Sections – The relative number [0 – 1] of required valid sections on a tracked line in order to

extrapolate missing point positions. Out of range values are treated as truncated.

7.3.1.6 Other

This contains all parameters, which do not have their own sub-section.



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Evaluate Pattern Quality – Indicates whether the quality of correlation pattern should be evaluated individually

for each marker and visualized as color of the displayed template.

7.3.2 Width Measurement

This section contains the parameters of width measurement.

7.3.2.1 Neck Detection

This sub-section contains the parameters of neck detection.

Select Longest Section – If enabled, selects the longest section instead of the shortest one.

Selection Mode – Specifies the criterion by which to select the section for analysis. By default, the section is

selected by the absolute length. The other options are to select it either by the absolute or relative change in

its length.

7.3.2.2 Width Detection

This sub-section contains the parameters of the detection of width points.

Automatic movement of width points – When turned on, width points are moved according to movement of

anchor points. This happens before correlation of locations of width points.

7.3.2.3 Width Correlation

This sub-section contains the parameters of correlation of width points. The correlation of these points takes place in time-

domain. For explanation of these parameters, see 7.3.1.1.

7.3.3 Calibration

This section contains the parameters of a calibration including the calibration grid for the definition of coordinate system,

the correction of distortions and the mapping of physical units. The calibration grids are displayed in Figure 99. Grids with

attached QR codes have the capability of automatic detection of their parameters, so they do not have to be set manually.

The calibration grid dialog appears automatically when starting a new camera calibration as well as when opening the

Coordinate System window. This dialog is the only place in the program, where these parameters can be modified!

Grid Type – Specifies the type of the calibration grid. Can be one of the following:

o Chessboard – Black and white squares. Whole grid must be visible.

o Circle Grid – Black circles in a regular grid. Whole grid must be visible.

o Enhanced Circle Grid – Black circles in a regular grid with three enhanced circles. The enhanced circles

must be visible. Currently, this type of grid is supplied with the software.

o Automatic Grid Type – The detection algorithm iterates through all available types until the correct one

is found.

Grid Width/Height – Number of inner square corners or circles on the calibration grid in horizontal/vertical

direction. This value is ignored when an enhanced circle grid is used.

Unit Distance – Size of a single square or distance between circle centers in physical units (mm).

Detection Method – Method of the grid detection. Is comprised of the following:

o Fast Simple – The fastest detection with the lowest accuracy.

o Fast Complex – Fast detection with decreased accuracy.

o Accurate Simple – Slow detection with increased accuracy.

o Accurate Complex – The slowest detection with the highest accuracy.



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Radial Distortion Coefficients – Number of calibrated radial distortion coefficients.

Figure 99: Calibration grids.

7.3.4 Full-Field Measurement This section contains the parameters of measurement with full-field measuring tools.

Compute All Values – Indicates whether to compute all supported graph data values in addition to the already

selected ones, so the selection can later be changed without having to recompute the data. Disable this option

in case the maximum computational performance is desired.

Minimum Angle of Boundary Triangles – Sets minimum angle (in degrees) of boundary triangles. This turns on

filtering of sharp triangles that often lead to less accurate results.

Maximum Allowed Strain – The maximum allowed value of computed strain values for them to be considered

as valid (in units of percent).

Filter Areas – Enables filtration (smoothing) of computed area. Currently only strains are filtered.

Filter Areas: Sigma – The sigma [mm] of the Gaussian kernel used for the filtration of areas.

Tensor Type – The type of the computed tensors when strain computation is enabled.

3D Tensor Computation Method – The method of computing tensors in 3D. Each method supports evaluation

of different tensor values. Can be one of the following:

o Full 3D – Deformation 'out of surface' is estimated so that volume is constant. Then full 3D tensors are

computed for this deformation. All tensor values are supported.

o XY-Plane – The specimen is placed in the XY plane (usually using the custom coordinate system) and

surface tensors are computed in this plane. Z movement is ignored. Supported tensor values are

StrainE1, StrainE2, StrainEXX, StrainEXY, StrainEYY.

Unit distance

Circle grid with QR

code (12x9) Unit Distance

Chessboard (9x6)

Enhanced Circle Grid Unit distance



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o Local Surface Tensors – A local plane is estimated for each measured point of the specimen. Surface

tensors are computed in this plane. Supported tensor values are StrainE1, StrainE2.

Deformation Computation: Used Points – Number of additional points used to compute a deformation in a

single point. A deformation cannot be computed for values less than 2. Higher values increase accuracy but

decrease locality.

7.3.5 Marker Detection This section contains the parameters of marker detection.

Type – The type of detected markers. Can be set to one of the following options, which are also previewed in

Figure 97:

a) Circle Marker – Detects circle markers on the surface of the specimen.

b) QR Code – Detects QR codes on the surface of the specimen. The resulting markers are then named after

the detected codes.

c) Cross – Detects contrasting crosses in the image.

d) Dot – Detects contrasting dots in the image.

e+f) Line – Detects the specified number of lines with either vertical or horizontal direction.

g+h) Edge – Detects the specified number of edges with either vertical or horizontal direction.

i) Marked Line – Detects lines with a specific tip.

a) b)

c) d)

e) f)

g) h)

i)

Figure 100: Marker detection types – a) circle marker, b) QR code, c) cross, d) dot, e) vertical lines, f) horizontal lines, g) vertical edges, h) horizontal edges and i) marked line.

Automatic Pairing – Type of automatic pairing of detected markers. It determines the desired length of resulting

extension lines as shown in Figure 101. Note that only specific cases of marker placement may effectively utilize

this feature. Can be set to one of the following options:

o Off – Deactivates the automatic pairing.



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o Shortest – Pairs the detected markers in such a way, that the resulting lines are as short as possible.

o Optimal – Pairs the detected markers in such a way, that the resulting lines are neither the shortest nor

the longest.

o Longest – Pairs the detected markers in such a way, that the resulting lines are as long as possible.

o Random – Pairs the detected markers randomly.

a)

b)

c)

Figure 101: Automatic pairing types – a) shortest, b) optimal and c) longest.

7.3.5.1 Line

This sub-section contains the parameters of line detection.

Line direction – Direction of detected lines (vertical or horizontal).

Number of lines – Maximum number of detected lines. A value of 0 denotes the detection of any number of

lines.

Center of detection – Relative position of center of detection ([0, 0] is top left and [1, 1] is bottom right) around

which lines are detected.

Minimum length of line in mm – Minimum length of line in millimeters. (not applicable in stereo)

Maximum length of line in mm – Maximum length of line in millimeters. (not applicable in stereo)

7.3.5.2 Edge

This sub-section contains the parameters of edge detection.

Number of edges after center – Maximum number of detected edges after (to the right or bottom) center of

detection.

Number of edges before center – Maximum number of detected edges before (to the left or top) center of

detection.

Center of detection – Relative position of center of detection ([0, 0] is top left and [1, 1] is bottom right) around

which edges are detected.

Edge direction – Direction of detected edges (vertical or horizontal).

Maximum distance from center – Maximum distance between detected edge and center of detection in pixels.



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7.3.6 Point Filtering This section contains the parameters of point filtering.

Filter Type – Type of the filter applied for point filtering during computation. This option is not applicable in

calibration projects.

Filtered Time Window Size [s] – Size in [s] of filtered history. Not applicable in combination with batches

averaging.

Filter Only Valid Samples – Specifies whether to return the resulting value as invalid if any point in the filtered

sequence is invalid. This is enabled by default and recommended when measuring moving specimens.

7.4 Other Controls

Factory Reset – Resets the values in the respective settings (system, presentation or computation) to their

factory defaults.

Save as Defaults – Saves the values in the respective settings (presentation or computation) as defaults.

Load Defaults – Resets the values in the respective settings (presentation or computation) to their defaults.



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Examples

Mercury RTⓇ allows to browse illustrative examples, which demonstrate the software capabilities and typical use-cases.

The examples are published via internet. This way provides the access to our library of online examples, guaranteeing up-

to-date examples. It is possible to download an example to hard drive and explore the results and settings. User can try

different settings, compare the results and revert the local changes to the original example state.

The available examples can be found in the Examples Browser window shown in Figure 102. Both remote and local sources

of examples can be specified:

Remote Source – Specifies the URL address of the available examples. Our online library of examples is located

at http://www.mercuryprogram.eu/download/examples/.

Local Source – Specifies a local folder where the examples are downloaded. The default location of the

downloaded examples is in My Documents\MercuryRT\examples\. It is possible to choose a custom folder

directly from the Examples Browser window by pressing the […] button.

When changing the remote and local source, it is required to press the Refresh button for the changes to take effect. After

that, the modifications are saved and will be used next time the Examples Browser window is open. The changes of the

remote and local source settings can be reverted by using the corresponding button in the bottom-left of the window.

There is also an option named Reset to default in the context menu of remote and local textboxes. The remote and local

source can be defined in the System Settings under Examples (see 7.1.9) as well.

Figure 102: The Examples Browser window showing a tree structure of categories and highlighted downloaded examples (bold font) and out of date examples (red color).


http://www.mercuryprogram.eu/download/examples/


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The examples are divided into several categories. This division is represented by a tree structure, which forms the main

part of the Examples Browser window. A particular example is the leaf of tree structure and can be recognized by the

icons , . The examples may be in several different states. The explanations of the possible states are as follows:

- This example is not downloaded yet.

- This example is already downloaded.

- This example is downloaded and has already been open and modified.

- This example is downloaded and has been already open and modified, but

there is a newer version of the example in the library of online examples.

When an example is selected, the Selected Example section of the window is updated with the information about the

selected example. Besides the example name, there is a description of the example. There are several options on what to

do with an example:

Open Example – Opens the selected example. If the example has not been downloaded yet, it is downloaded

and then opened.

Download – Downloads the selected example to a local source.

Revert Project File – Reverts changes of the selected modified example.

Delete from disk – Deletes the selected downloaded example from a local source.



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Test Rig Configuration

This chapter provides a detailed description of the configuration of testing machines which can be utilized for the testing

of material properties.

9.1 Active Test Rig

The type of the active measuring device and several other parameters adjusting its configuration can be specified in System

Settings (shown in Figure 103). It is possible to connect a Doli EDC device, a SobriECU device, one of the four types of

supported analog inputs or a digital input using a serial COM port. For further explanation of the associated parameters,

see 7.1.4.

Figure 103: System Settings - Test Rig parameters.

9.2 Doli EDC / SobriECU

The following chapter is a description of all controls, which are made accessible when using a DOLI DoPE or a SobriECU

driven testing machine, as well as all attributes which have to be set before running a new test with it. To select the testing

machine, specify the Doli EDC or the SobriECU option as the active test rig.

9.2.1 Test Rig Panel Represents a tab in the main window which provides the means to control DOLI DoPE driven testing machines. The

recording of all displayed data takes place automatically when a test is running, regardless of the movement of the testing

machine’s cross-head.



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The explanation of the controls within the Test Rig panel illustrated in Figure 104:

Force [N] – Displays the actual force being applied to the test specimen in real-time.

Position [mm] – Displays the actual position of the testing machine’s cross-head in real-time.

Extension [mm] – Displays the actual extension of the tested specimen in real-time.

Tare (Force/Position/Extension/All) – Resets the specified testing machine sensors.

Preload – Applies the preload value as set in the preset configuration window. (see 9.2.2.3)

Cross-Head Up/Down – Adjusts the position of the testing machine’s cross-head. An alternative to these buttons

is provided by the means of scrolling the mouse wheel button, which can be activated by its corresponding

button on the right and may also be done with an increased speed by keeping a Ctrl button held down.

Halt Cross-Head – Stops the movement of the testing machine’s cross-head.

Test Rig Settings – Displays a detailed configuration window of the testing machine. (see 9.2.2)

Active Preset – Contains a list of created presets with the currently selected one applied during the

measurement.

Auto Run – Toggles the option to activate the movement of the testing machine’s cross-head automatically by

the Run button in the project controls, right before starting an actual test in which the recording of measured

values takes place.

Free Run – Activates the movement of the testing machine’s cross-head with the active preset settings. Please

note, that the data measured this way are not recorded unless a new test is started by the Run button among

project controls.

Figure 104: The Test Rig panel – Active Test Rig: Doli EDC.

9.2.2 Preset Configuration The testing machines have their specific settings stored in the form of special configuration files called presets, which are

selected independently of the currently open project. The detailed properties of the testing machine can be adjusted

through the Test Rig Presets dialog.

The controls located in this dialog are specified as follows:

Create – Creates a new testing machine preset. When pressed, a dialog appears, prompting to specify whether

to copy the settings of the currently selected preset or to use defaults.

Import – Imports a previously created configuration file.



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Delete – Deletes the selected preset.

9.2.2.1 Sample Settings

The Sample settings tab includes the calculator of the specimen’s cross-section as well as an option to use this parameter

for the computation of stress and strain.

Specimen shape – There are three basic predefined specimen shapes, namely circular, rectangular and tube.

The dimensions of a particular shape are entered in the box below. The cross-section is then calculated

automatically. In case of some other specimen shape, the cross-section is entered as a pre-computed value.

Stress/Strain – To ensure the computation of stress and strain values by using the values measured by a test rig,

the appropriate checkboxes must be checked and the reference length L0 filled in.

Figure 105: The Sample settings tab.

9.2.2.2 General Settings

The General settings tab of the shown in Figure 106 contains mostly parameters related to the speed and direction of the

testing machine’s cross-head. It is divided into several sub-sections described underneath.

Preset Name – Contains a modifiable name of the configuration file. Must be unique.

Test X-head Movement – Adjusts the direction of the movement of the cross-head, effectively specifying the

type of the test (tension or pressure). Can be either upwards or downwards.

Speed – Adjusts the speed of the cross-head under the following circumstances:

o During Test – The speed utilized during the test.

o Manual Control Slow – The speed during a manual control.

o Manual Control Fast – The speed during a manual control when a Ctrl button is held down.

Mouse X-head Movement – Adjusts the speed of the cross-head when scrolling the mouse.

o Slow Step – The slow step speed of the cross-head.

o Fast Step – The fast step speed of the cross-head (when a Ctrl button is held down).



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Figure 106: The General settings tab.

9.2.2.3 Preload Settings

The Preload settings tab shown in Figure 107 contains the parameters of the preload applied to the specimen. These are

applied when the Preload button of the test rig tab is pressed (see Figure 104).

Figure 107: The Preload settings tab.

Preload Parameters – This sub-section contains the following:

o Preload Speed – Adjusts the speed of the cross-head during a preload.

o Position Limit Mode – Specifies whether an absolute or a relative extension limit is applied to the

specimen. If the position limit mode is active, such condition is considered as well, in addition to the



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specified destination load. The fulfillment of either one of the specified conditions signifies the

completion of the preload process.

o Position Limit – Adjusts the value of the position limit applied to the specimen. The control is available

only if the position limit mode is active.

o Destination Load – Adjusts the value of the target load applied to the specimen.

9.2.2.4 Cycling Settings

The Cycling settings tab shown in Figure 108 contains the parameters of an optional periodical repetition of the testing

machine’s cross-head. These are applied during the test. Some parameters are support only by DOLI EDC or SobriECU.

These differences are mentioned in the following text.

Figure 108: The Cycling settings tab.

Enable cycling – Toggles whether the cycling parameters are active and applied. By default, this option is NOT

active.

Cycling parameters – This sub-section contains the following:

o Wave Form – The wave form of the cycle.

Types supported by DOLI ECU: Cosine, Triangle, Rectangle, Saw tooth, Saw tooth inverse,

Pulse.

Types supported by SobriECU: Sine, Cosine, Triangle.

o Sensor – The type of sensor which controls the test.

o Relative – Indicates whether the values are relative or absolute.

o Speed to Start [Unit/s] – Specifies how fast the testing machine will reach the starting position of cycle.

o Amplitude – The amplitude of the cycle. An amplitude lower than 0 starts the test from a negative value.

o Halt at Plus Amplitude [s] – Specifies how long to stay at a positive amplitude.

o Halt at Minus Amplitude [s] – Specifies how long to stay at a negative amplitude.

o Frequency – The frequency of the cycle.

o Offset – The offset of the cycle.

o Cycle count – The number of cycles. A value of zero means infinity.



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o Frequency Sweep (supports DOLI EDC only) – The sweep of frequency. Specified by Mode, End value,

Time and Count.

o Amplitude Sweep (supports DOLI EDC only) – The sweep of amplitude. Specified by Mode, End value,

Time and Count.

o Offset Sweep (supports DOLI EDC only) – The sweep of the offset of the selected sensor type. Specified

by Mode, End value, Time and Count.

o Superposition (supports DOLI EDC only) – An option to superimpose all waveforms with a cosine wave.

Specified by Mode, Frequency and Amplitude.

o SoftLoop control (supports DOLI EDC only) – SoftLoop allows to run the test in e.g. position control, but

keep a certain e.g. load. The load is controlled by changing the offset of e.g. position. Specified by Mode,

a control Sensor, one or two Values depending on the mode and Scale.

9.2.2.5 Channel Supervision Settings

The Channel Supervision settings tab shown in Figure 109 contains the parameters of an optional automatic stop of the

cross-head after a defined termination condition is met. Each of the termination conditions takes into consideration a

specified limit of a value on one of the input sensors.

Figure 109: The Channel Supervision settings tab.

Enable Channel Supervision – Toggles whether the channel supervision parameters are active and applied. By

default, this option is NOT active.

Channel Supervision Parameters – This sub-section contains the following:

o Sensor – Specifies the type of the sensor to be supervised.

o Termination condition – Specifies the condition of the termination to be fulfilled. Can be set to one of

the options described in Figure 110.

o Limit – Specified the limit value referred to in the termination condition.

The above condition is applied… – Toggles whether the additional condition is active and applied. By default,

this option is NOT active.



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Additional Condition – This sub-section contains the same parameters as the previous one. If checked, the above

condition is applied when following condition is hit. In this case, the test terminates when both conditions are

hit in the given order.

Figure 110: The terminating conditions of selected sensors.

9.3 Analog / Digital Input

The analog or digital inputs are other options on how to retrieve values from a testing machine. Mercury RTⓇ supports

MCC and Advantech A/D converters for an analog input, as well as a Tensoamp device. Further information about the

Tensoamp device can be found in chapter 10.3.2. A digital input is realized using a serial communication (COM port). Active

Test Rig (see 9.1) has to be set to the appropriate option:

Mcc Analog Input or Advantech Analog Input for getting data from an A/D converter.

Tensoamp Analog Input or Tensoamp Analog Bridge Input for getting data from a Tensoamp device.

Digital Input for getting data using a serial communication.

9.3.1 Test Rig Panel The Test Rig panel only serves to display data from the analog or digital input in case of the absence of a testing machine

supporting DOLI DoPE or SobriECU. The control of the cross-head of a testing machine is not possible, therefore the control

buttons are disabled. Only the Tare button is enabled for resetting the values (see Figure 111).

Figure 111: Test Rig panel – Active Test Rig: Mcc Analog Input.

9.3.2 Digital Input Format Description

The format of a digital input from a test rig to Mercury RTⓇ via a COM port is described below.

Message delimiter \x04 (EOT)

Value delimiter ;



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Value order load [N], position [mm], extension [mm], sensor3 [-],

sensor4 [-], sensor5 [-], sensor6 [-], sensor7 [-]

Valid examples 1559.12\x04

1559.12;15.3\x04

1559.12;15.3;2.3;3;4;5;6;7\x04



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I/O Services

This chapter describes the setup of I/O Services. Mercury RTⓇ allows to send user defined values of measured quantities

to a selected output. Described are the configuration options of the analog, digital, DOLI Binary Serial and Test Rig outputs,

as well as HP Video and Remote Control API protocols.

The configuration of services is handled by the I/O Services panel illustrated in Figure 112, which is situated in the main

window. Any new added I/O service is shown in the Active Services list. If a service is properly configured, a green circle

will appear next to its name. A connection error of an I/O service is indicated by a red circle. The description of the error is

shown in the tooltip of the service. If a service is manually stopped, the circle turns grey. Additionally, each created service

can be edited or deleted via the buttons at the bottom of the panel.

Figure 112: The I/O Services panel.

10.1 Adding a New Service

It is possible to choose from several kinds of services which differ in the way of communication. For a proper function of

each available service, it is necessary to specify the connection parameters. Moreover, some of the services allow the

adjustment of the output format. The service parameters are adjusted using the Add I/O Service wizard, which is displayed

in Figure 113. There is no restriction to the number of added services of the same type with the exception of a Remote

Control API, which can only be added once.

Starts/Stops the selected

service

Displays the selected service

Adds a new service

Edits the selected

service

Removes the selected

service



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Figure 113: The Add I/O Service wizard.

10.1.1 Analog Output Service The Analog Output service allows to send a single value via a D/A converter. The value is sent every time new data are

computed, namely during real-time tests and recomputations. Mercury RTⓇ supports D/A converters from Advantech and

MCC manufacturers, as well as DigiGauge devices. Before using an MCC converter, the Instacal program included in the

Mercury RTⓇ installation file must be used to create a configuration file! The Analog Output service has several parameters,

which are configured in the Add I/O Service wizard shown in Figure 114. The parameters are described below.



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Figure 114: Add I/O Service wizard - Analog Output service parameters.

Analog Output Device – Specifies the type of the used device and must be set to one of the supported D/A

converters. The converter can be selected either from MCC or Advantech, or alternatively a DigiGauge converter

can be used instead.

Device Number – The number of the analog device used for analog output. Applicable only for an MCC or

Advantech device.

DigiGauge connection – The parameters of the COM port connection to a DigiGauge device. They all represent

settings of the used COM ports and are as follows: Port Name, Baud Rate, Parity, Data Bits, Stop Bits and

Handshake. Specify an empty string as port name to set the COM port as none.

DigiGauge Buffer Delay [ms] – The buffer delay and camera FPS determines the number of samples to be

buffered before the data is sent to the output. If no data is computed before the delay timeouts, the data is sent

to the output without buffering.

10.1.2 Digital Output Service The Digital Output service allows sending either up to eight selected measured values or all measured values. The service

offers two types of connection – TCP/IP or a COM port (Figure 115). In addition, the user can adjust the output format of

sent messages according to his specific requirements for both types of connection.

Figure 115: The available connection types of the Digital Output service.



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10.1.2.1 TCP/IP

The TCP/IP variant of the Digital Output service listens for an incoming connection on the specified address and port and

sends a message in a user defined format every time some new data is computed, namely during real-time tests and

recomputations. The service has several parameters, which are configured in the Add I/O Service wizard and shown in

Figure 116. They represent the settings of a TCP/IP connection, namely the Server Address and a Port Number, and the

output format:

Message Delimiter – Delimits the entire message, i.e. one package of data for one-time moment.

Value Delimiter – Delimits each computed value.

Not Computed Value – Specifies the value which is used for null, i.e. not computed values.

Decimal Places – Specifies how many decimal places to include in the formatted output.

Decimal Point – Specifies which symbol to use as a decimal point.

Example of a sent message:

Figure 116: The parameters of a TCP/IP connection with an output format.

10.1.2.2 COM Port

The COM port variant of the Digital Output service runs on a specified COM port and sends a message in a user defined

format every time new data is computed, namely during real-time tests and recomputations. The service has several

parameters, which are configured in the Add I/O Service wizard shown in Figure 117. They represent the settings of a COM

port and the output message format. The settings of a COM port include Port Name, Baud Rate, Parity, Data bits, Stop

bits and Handshake. They must correspond with the COM port settings in the operation system for its proper function.

The output message format consists of the same items as in 10.1.2.1.

5.701||126.8609\r\n

The example uses the default output format. The message starts with the

first value (5.701). Two value delimiter ‘|’ signs follow, which means the

second value is not computed. After that, the last value (126.8609) follows.

The end of message is specified by the message delimiter \r\n.



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Figure 117: The parameters of a COM port connection with an output format.

10.1.3 DOLI Binary Serial Output Service The DOLI Binary Serial Output service implements the DOLI protocol for sending up to four measured values to a DOLI EDC

device. The configuration of parameters can be done in the Add I/O Service wizard illustrated in Figure 118. These are the

parameters for the formatting of measured values and for the COM port used for the communication with a DOLI EDC

device. The settings of a COM port include Port Name, Baud Rate, Parity, Data bits, Stop bits and Handshake. They must

correspond with the COM port settings in the operation system for its proper function. The measured values are formatted

by the multiplication Float Factor. It determines how many decimal places of the measured values are preserved. Use the

same value as configured in the corresponding DOLI EDC device.

Figure 118: The DOLI Binary Serial Output service configuration.

10.1.3.1 Supported commands for DOLI Binary protocol

The DOLI Binary Serial Output service also supports the following commands. With these commands, it is possible to

control Mercury RTⓇ from an external software by using DOLI electronic without the need for manual input in the software.

S = Starts a new measurement.

Q = Stops the currently running measurement.



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L = Followed by a decimal number, sets the length of all applicable length-measuring probes (also known as the

initial gauge length).

T = Followed by a decimal number, sets the width of all applicable width-measuring probes in the first camera

configuration of the currently open project (e.g. the initial width).

W = Followed by a decimal number, sets the width of all applicable width-measuring probes in the second

camera configuration of the currently open project (e.g. the initial thickness).

10.1.4 Test Rig Output The Test Rig Output service can be used to output specified values to the control unit of the connected test rig. This is then

used by some of the units to control the movement of the cross-head. The only parameter in this option is the Sending

Interval [Hz], which indicates how often the measured values are sent to the test rig. A large rate can lead to an overload

of the communication channel. Consider using the value filtering feature to reduce the communication with the test rig.

10.1.5 HP Video Service

The HP Video service implements the HP Video protocol for a bi-directional communication between Mercury RTⓇ and

another application implementing the HP Video protocol. The service allows the transmission of up to four values via a

COM port. The COM port configuration can be done in the Add I/O Service wizard illustrated in Figure 119. The settings of

a COM port include Port Name, Baud Rate, Parity, Data bits, Stop bits and Handshake. They must correspond with the

COM port settings in the operation system for its proper function.

Figure 119: HP Video Service configuration.

10.1.6 Remote Control API Service

The Remote Control API service allows to control Mercury RTⓇ either via TCP/IP or a COM port communication. Only one

instance of the service can be running at a time. The documentation with a detailed description of the API communication

protocol is available as a separate file on http://www.sobriety.cz/t_optical_systems_en.htm.

10.1.6.1 TCP/IP

The TCP/IP variant of the API service listens for an incoming connection on the specified address and port, and sends

messages in a user defined format. The parameters of the service can be configured in the Add I/O Service wizard shown

in Figure 120. These are the settings of a TCP/IP connection, namely Server Address and Port Number, and the message

output format consisting of the same items as in 10.1.2.1.


http://www.sobriety.cz/t_optical_systems_en.htm


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Figure 120: The Remote Control API service - TCP/IP configuration.

10.1.6.2 COM Port

The COM port option of the API service runs the service on the specified COM port and sends messages in a user defined

format. The parameters of the service can be configured in the Add I/O Service wizard shown in Figure 121. These are the

settings of a COM port and the output message format. The settings of a COM port include Port Name, Baud Rate, Parity,

Data bits, Stop bits and Handshake. They must correspond with the COM port settings in the operation system for its

proper function. The output message format consists of the same items as in 10.1.2.1.

Figure 121: The Remote Control API Service - COM port configuration.



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10.2 Configuration of the Output Values

The settings of the output of particular measured values can be specified in the Graph Data panel on the left of the main

window. Each measured value in the panel illustrated in Figure 122 has a Settings button on the right side. The color of

this button shows whether the value is sent to output and its tooltip also shows which specific output that is, possibly even

if there is a visual alarm set for the value (see 2.6.1). Press any Settings button for an access to the activation of individual

measured values.

Figure 122: The Graph Data panel with measured values and an output signalization.

After pressing the Settings button, a Graph Data Settings dialog appears. The list of the active services is shown on the

left side of the dialog. The Digital Output service and the Remote Control API service can send either all computed values

simultaneously or up to eight measured values labeled A – H (illustrated in Figure 123).

Figure 123: The output values of the Digital Output service.

The Analog Output service can send up to eight measured values labeled A-H, initially corresponding with the channels on

the D/A converter numbered 0-7 as illustrated in Figure 124. Furthermore, the following parameters especially about the

recalculation between the measured values and the measuring range of the D/A converter must be specified as well:

Channel Number – The number of the channel for analog output. Indexed from zero.



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Min Output Value Absolute – The minimum for values in absolute units sent via analog output. Lower values

are clipped to this value. If an absolute value is sent to the output, sets the value assigned to the minimum of

the analog range. For example, if set to 10 and the analog range is ± 10 V, a value of 10 will be assigned -10 V.

Max Output Value Absolute – The maximum for values in absolute units sent via analog output. Higher values

are clipped to this value. If an absolute value is sent to the output, sets the value assigned to the maximum of

the analog range. For example, if set to 85, and the analog range is ± 10 V, a value of 85 will be assigned 10 V.

Min Output Value Relative – The minimum for values in relative units [%] sent via analog output. Lower values

are clipped to this value. If a relative value is sent to the output, sets the value assigned to the minimum of the

analog range. For example, if set to -5, and the analog range is ± 10 V, a value of -5 % will be assigned -10 V.

Max Output Value Relative – The maximum for values in relative units [%] sent via analog output. Higher values

are clipped to this value. If a relative value is sent to the output, sets the value assigned to maximum of the

analog range. For example, if set to 85, and the analog range is ± 10 V, a value of 85 % will be assigned 10 V.

Figure 124: The Output values of the Analog Output service.

The HP Video service can be adjusted to send up to four measured values as specified by the HP Video protocol (illustrated

in Figure 125):

L – Extension value.

Q – Transversal strain value.

A – Second extension value.

B – Second transversal strain value.



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Figure 125: Output values of the HP Video service.

The DOLI Binary Serial Output service allows the transmission of up to four values A-D (illustrated in Figure 126).

Figure 126: The output values of the DOLI Binary Serial Output service.

After closing the settings window, the selected output values turn green. A green color indicates the values sent to any

output. The associated output services are shown when moving the mouse over the I/O button. It is possible to readjust

all output settings whenever the values are currently not being computed.



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Figure 127: Green highlighted output values associated with an output service in the Graph Data panel.

10.3 Mercury RTⓇ I/O Accessories

10.3.1 DigiGauge DigiGauge is a device with a full software set-up serving as a 16-bit D/A converter providing time-synchronized analog

outputs and a signal conditioning (processing). It can be used to simulate a strain gauge as well. It features an open source

communication protocol. The devices are made in 1, 2 or 4 channel configurations.

Two types of outputs are possible:

1) A standard ±10 V analog low-impedance output.

2) A strain gauge emulated low-voltage differential output. It can be connected to any strain conditioners up to

1000 ohm. The bridge output is powered by external 5V excitation, is galvanically isolated and features a 1000

ohm full-bridge emulation.

The output differential range: ±200 mV/V, ±20 mV/V or specified by a customer.

DigiGauge may be used for the types of test machines which have neither digital nor analog input but have a support for

foil strain gauges. Moreover, it can be used for the calibration of strain gauge amplifier. Any bridge type sensor amplifiers,

converters and conditioners may be connected.

10.3.2 TensoAmp

TensoAmp is another device designated for use with Mercury RTⓇ. It is a 16-bit A/D converter featuring 1-4 channels, with

variable oversampling and a full software set-up. Provides a signal conditioning for up to 4 strain gauges or various other

bridge sensors. It can work as a ¼, ½ or full bridge.

There are two types of analog inputs:

1) A standard ±10 V high-impedance input.

2) A bridge connection of various strain gauges, load cells, pressure sensors and any other bridge type sensors.

Each bridge input is digitally configured and may be connected with bridge completion resistors (120 ohm,

350 ohm and 1000 ohm) included in the device. Programmable sensitivity settings 0.03-290 mV/V correspond



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to a strain range with approximately 60-580 000 µm/m. Offers programmable excitation with fixed 3 V, 5 V or

variable DAC 1.8 V to 5 V setting.

Two types of outputs are possible:

1) A standard ±10 V low impedance analog output (a fully analog signal path, a programmable gain).

2) A digital sampling (a 16-bit A/D converter with variable oversampling).



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Extensometer Calibration

Apart from the calibration of camera distortions and the coordinate system, Mercury RTⓇ also offers an advanced feature

named Extensometer Calibration. It represents a way to perform a correction of the positions computed in physical units

using externally measured positional data, which is entered manually into the program alongside the respective computed

data. Such a definition needs to be performed only once in a specialized extensometer calibration measurement and its

output is an extensometer calibration file. This file can then be loaded in other projects, which use the same hardware

setup as the project, in which the extensometer calibration was performed. The detailed description of all these steps is

provided below.

Figure 128: The Real-time Extensometer Calibration option in the main menu.

11.1 Creating an Extensometer Calibration Measurement

The extensometer calibration measurement is a special type of a project, which provides only the tools required for the

definition of the extensometer calibration. Most importantly, this includes the optional calibration of camera distortions

and the coordinate system, but excludes the input of tracking probes. Only a specialized calibration probe is available in

each of the camera displays in the calibration measurement, which is being tracked in the same way as a usual point probe.

If there is already a measurement available, which uses the same hardware setup and will be expected to use the

extensometer calibration afterwards, it will have to be manually ensured, that the newly created extensometer calibration

project uses the same calibration of camera distortions and the coordinate system as those measurements.

11.2 The Definition of the Extensometer Calibration

Once the extensometer calibration measurement is open and both the definition of the coordinate system and the

calibration of camera distortions are set as desired (although neither one of them is mandatory), it is required to move the

specialized calibration probe to a position, where it can be tracked by Mercury RTⓇ and have its displacement measured

outside the program as well. The actual recording and computation is then performed as usual, by pressing the Run button

in the project controls panel located in the main window (see 2.4). The only difference here is that only the Run in Snap

Mode option is available in order to allow the frames to be captured when the calibration probe is in a position where its

precise value of displacement is known from outside the program.

To assist with the manual input of externally measured values of displacement, the Extensometer Calibration panel is

available on the right side of the main window, as displayed in Figure 129. It is, however, also shown automatically when

running a test in an extensometer calibration measurement, so it is available right when it is needed. The first drop-down

controls in this panel determine, which scene and axis are being calibrated at the time and only the latter is visible in a

project containing just a single scene (a mono camera, a stereo camera or a mono stitching). While all the scenes in a

project have their extensometer calibrations defined separately, only the selected axis is considered for a given scene. In

conclusion, this means that only the deformations taking place in the selected axis will be corrected by the defined

extensometer calibration.



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Figure 129: The Extensometer Calibration panel.

Spanning through the middle of the panel is a table filled with the displacements of the calibration probe computed in

Mercury RTⓇ in the left column, while the right column in mostly left blank for the manual input of externally measured

displacements of the probe in those specific positions. If the batch size was set to a higher number than one before the

recording of the frames, the values displayed in the left column represent the average of the computed displacement in

that batch. The manual input of values to the right column can be done anytime, either directly during the recording of the

frames in snap mode or afterwards. Clicking on a row with values also moves the project seeker to the corresponding

moment in time.

The buttons located at the bottom of this panel are described as follows:

Show standard deviation – Replaces the values in the right column of the table above with a display of the

standard deviation of the computed displacements of the calibration probes in the associated batch. This option

is only available if the batch size is higher than one. Click on the button again to restore the values in the right

column of the table back to the input of externally measured displacements.

Save as – Saves the configured definition of the extensometer calibration to a specified XML file. If this file is

saved directly to the data directory of a project, where the extensometer calibration is to be used, it will be

loaded automatically when opening that project. The same file is also available in the data directory of the

project, where the extensometer calibration was defined.

Save to all measurements – Saves the definition of the extensometer calibration to the data directory of all

measurements contained within the same directory as the current project. These files are automatically loaded

when opening those projects.

11.3 Using the Extensometer Calibration

When an extensometer calibration is loaded in a project, it will automatically perform a correction of physical units

computed for the positional data in the axis for which it was configured. The indication of whether an extensometer

calibration is active in a project and in which axis it takes place is located at the bottom a of scene window as shown in

Figure 130.

Figure 130: Status indication of the extensometer calibration.



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Currently, it is up to the user to ensure that the measured deformations will take place predominantly in the given axis.

Also, as mentioned above, the extensometer calibration is only valid in combination with the calibration of camera

distortions and the coordinate system it was associated with during its configuration. As a consequence, it is not possible

to change any of these if an extensometer calibration is loaded in a project. To undo this effect, as well as to see in which

axis the system is calibrated in, press the Unload Extensometer Calibration button located in the Scene Setup panel of a

scene window. If no extension calibration is used at the moment, this button is replaced by a Load Extensometer

Calibration button, which loads the extensometer calibration from a specified XML file.



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HW Synchronization

12.1 Introduction

Most of the time, the internal camera synchronization is all that is needed. This means that when a certain FPS value is set

for a camera, an image is taken in each corresponding interval after starting to capture. This is sufficient for low-speed

single camera tests. However, other scenarios may require some sort of synchronization, for instance:

A cycling test where an image is taken in a certain phase after a given number of cycles.

High-speed tests where the start must be precisely given.

Multi-camera set-ups, especially stereo cameras, where images from the left and from the right camera must

be taken at the exact same time.

The capture of vibration tests using regular speed cameras where a phase must be sampled in precisely given

intervals.

The HW synchronization is about sending an electrical signal to the camera input pin to signalize when an image is to be

taken. Please note that not all cameras support every option of synchronization.

12.2 Camera Synchronization Panel

The external synchronization of a camera can be toggled by checking the Enabled box in the Cameras panel on the right

of the main window, as seen in Figure 131. This enables the last used synchronization. If the synchronization options need

to be adjusted, this can be done in System Settings under Cameras (see 7.1). The individual parameters of synchronization

are described in the following chapters.

Figure 131: Camera Synchronization panel.

12.2.1 Camera Synchronization Modes

Mercury RTⓇ supports the following modes, all of them illustrated in Figure 132:

FireWire Bus Synchronization – Valid only for FireWire cameras. Requires that all cameras are daisy chained on

a single FW adapter. The advantage is that no additional devices or cables are needed.

External Trigger – All connected cameras are switched into an external synchronization mode where they are

awaiting an electric pulse on an input. An external device is needed to trigger the cameras at the desired

moment. Works for any kind of camera interface.

Master/Slave – A synchronization mode where one of the cameras acts as a master identified by the Master

Camera Id (i.e. broadcasts a pulse at the very moment the camera started to capture its image) and all other



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cameras are set to a slave mode (corresponds to the External Trigger mode above). The camera, which is set as

master is indicated by a MASTER label in the header of its camera view. This mode does not require an external

device – a simple cable can do the job and hence increases the ease of use. Works for any kind of camera

interface.

a)

b)

c)

Figure 132: Schematic representation of HW synchronization set-ups. a) FireWire Bus Synchronization, b) External Trigger and c) Master/Slave.

12.2.2 Additional Synchronization Settings

Further synchronization options can be found in System Settings under Cameras (see 7.1.2).



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Figure 133: The Camera parameters section of the System Settings window.

12.2.2.1 Slave Camera Trigger

Contains additional settings used for the Master/Slave (slave cameras) and External Trigger (all cameras) synchronization

modes.

Input Pin Number – The number of the camera pin to receive the TTL pulse. If left at 0 when using most USB3

cameras, the default opto-isolated input line is put into use. This line has higher delays than the direct-coupled

line, so set this number to one of the GPIO pins if it is desired to have the lowest possible delay. (recommended)

Further remarks on use with specific camera brands are noted in the extended description of this parameter.

Input Pin Polarity – The polarity of the TTL pulse. Can either be set to Trigger on a Rising Edge or Trigger on a

Falling Edge.

Mode – The external triggering mode of the camera. Applied only when using AVT cameras. Can be set to one

of the following options:

o Fixed Shutter / Edge – The trigger signal starts the integration.

o Integration Enable / Level – The trigger signal determines the integration time. (the value of shutter

time is ignored)

o Bulk Capture – The trigger signal starts a series of integrations.

Camera Link Signal Input – The trigger signal input connector of Camera Link cameras. Currently applicable only

to cameras by Sentech. Can either be set to Camera Link (CC1) or Power/IO connector (No. 2 pin, SP4).



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Emit Software Trigger to High-Speed Cameras – Specifies whether to emit a software trigger of high-speed

cameras regardless of their synchronization settings.

12.2.2.2 Master Camera Trigger

Additional settings used only during the Master/Slave mode (the master camera).

Output Pin Number – The number of the camera pin to send the TTL pulse. If left at 0 when using most USB3

cameras, the default opto-isolated output line put into use. This line has higher delays than the direct-coupled

line, so set this number to one of the GPIO pins if it is desired to have the lowest possible delay. (recommended)

Further remarks on use with specific camera brands are noted in the extended description of this parameter.

Output Pin Polarity – The polarity of the TTL pulse. Can either be Inverted or Not Inverted. Inversion is not

applicable to PointGrey cameras.

PWM Duty Cycle [%] - Certain models of cameras (currently only IDS) use Pulse Width Modulation to generate

the trigger signal for slave cameras. This determines the value of the duty cycle, which is a parameter of the

PWM function. It is specified in units of %, where 1% means the narrowest pulse and 99% the widest.

The PWM function also has a frequency parameter, but it is computed automatically by using the FPS value set

for the camera.

12.3 Synchronization Box – Vibrography Applications

The Synchronization Box is a device, which is distributed separately. The box facilitates the analysis of high-speed periodic

phenomena using regular (non-high-speed) cameras, which significantly reduces the cost of the equipment. The main

application is a vibrography analysis of an excited specimen driven by a known periodic signal.

Figure 134 shows a typical connection of the synchronization box in a vibrography application. The source of the periodic

signal is a generator, which simultaneously sends the signal into a shaker and the box. The camera synchronization is

realized via the box according to the set of input parameters. The box determines the period of the input signal and sends

it to PC. Both cameras are connected to the output channels of the box. The communication between the PC and the box

is realized via a serial COM port.

Figure 134: The wiring diagram of the Synchronization Box.

The default operation mode of the box is the Phase Sweep Mode. The purpose of the box is to measure the input signal

frequency, report this to the PC for a proper timestamp computation and trigger the camera(s) in the exactly correct

moments to perform a so-called phase sweep. At the end, the specified number of “virtual” periods is recorded with correct

timestamps, so that a vibrography analysis can be computed. The resulting data should be almost as if it was recorded by



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a high-speed camera (provided the test is periodical and the excitation signal is available); the only limitation is that the

computed amplitudes are only valid for the excitation frequency and its harmonics.

12.3.1 Connection of the Synchronization Box The connection settings of the box are located in System Settings under Synchronization Box, as shown in Figure 135.

The only necessary step to connect the synchronization box is to insert a proper COM port name. Control of the

synchronization box is performed through an external application. Further information about this application is

provided as a separate document.

Figure 135: The Synchronization Box settings.

The individual items of these settings are as follows:

Connection – The COM port parameters of the connection with the device. They all represent the settings of

the COM port used for bi-directional communication with the connected Synchronization Box and are as follows:

Port Name, Baud Rate, Parity, Data Bits, Stop Bits and Handshake. Specify an empty string as a port name to

deactivate the Synchronization Box.



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High-Speed Camera Measurement

13.1 Connection of the High-Speed Camera

The current distributions of Mercury RTⓇ offer the opportunity of measuring with high-speed cameras. Utilizing high-

speed cameras together with the software gives new possibilities, especially when analyzing phenomena like vibration,

crash tests etc.

Example:

The connection of an Evercam high-speed camera to Mercury RTⓇ requires to take the following steps. Open Control

Panel / Network and Internet / Network Connections and determine, which adapter is related to the high-speed camera.

Edit Properties of the appropriate adapter and modify IP protocol version 4 according to Figure 136.

Figure 136: Setting the IP address of the camera.

Thereafter open Device Manager / Network adapters and select Properties of the same adapter as in the Network

Connections window. Firstly, set Jumbo Frame in the Advanced tab as 7KB or more (see Figure 137).



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Figure 137: Jumbo frame modification of the network adapter.

Secondly, fill in the gap of Network Address (Locally Administered Address) according to Figure 138. After these essential

steps, the Evercam high-speed camera only needs be activated in System Settings under Active Camera Libraries (see

7.1.1) and will be ready to use.

Figure 138: Setting the network address of the network adapter.



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13.2 Operating the High-Speed Camera

Operating a high-speed camera in Mercury RTⓇ differs from operating other cameras in the following way. When

measuring a scene, the video must be recorded first and only after that may the computation take place. Performing a live

measurement using a high-speed camera will only record a low-speed preview of the scene! To capture a sequence of

frames, click the High - speed Capture Tool button in the Cameras panel on the right of the main window to open the

High-Speed Capture Tool window depicted in Figure 139.

Figure 139: Opening the High-Speed Capture Tool.

In the upper toolbar of this window (displayed in Figure 140), there are a few controls, which are essential for recording.

The two most important parameters are FPS (frames per second) and Sequence Length, which can be set as a time interval

or as a number of captured frames. Pre-Trigger Length stands for the percentage of the frames recorded after clicking

Ready to be kept in the final sequence even after clicking the Record button. The Ready button prepares the camera for

recording by starting to store frames in the internal memory of the camera. The recording itself is started when clicking

the Ready button and stopped after clicking the Record button and when the sequence is finished afterwards. If the pre-

trigger is set as 0 %, only the frames captured after clicking the Record button are stored.

Figure 140: The High-Speed Capture Tool window.



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The lower toolbar includes several buttons in addition to the Ready and Record button. The selection of frames to be used

within the project is performed by dragging the controls on the slider or using the Set as Begin and Set as End buttons.

Because the relevant range of frames can be rather small compared to the entire recording, advanced options of seeking

are available here as well, allowing to browse through the recorded frames in larger increments. By clicking the Download

button, the final size of the sequence is computed and downloaded to the data directory of the project, making the

recording ready for adding probes and performing an analysis.



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Custom Series

14.1 Overview

Mercury RTⓇ provides a wide variety of computed values. Each probe has many different quantities, which can be turned

on by a simple mouse-click. However, for demanding users, this may still not be enough. Therefore, user-configurable data

series can be specified via the built-in Custom Series window, also known as Expression Editor. These custom series are

saved into a user folder and can be used in any project. The series can then be turned on and off independently for the

specified project. Data is displayed in the graphs and exported in CSV. The specification of custom data series can be sent

via email, downloaded from the Internet and easily imported.

14.2 Configuration Workflow

14.2.1 Expression Editor Access The Expression Editor is accessed by selecting the Configure Custom Series option in the graph panel’s context menu from

the main window as shown in Figure 141.

Figure 141: Access to the Expression Editor from the main window.

14.2.2 Adding a New Expression

The Custom Series window is open as seen in Figure 142. A new expression is added by clicking the Create button.



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Figure 142: The Custom Series window.

The window contains these sections, which are mandatory:

Name – Specify the desired name of the expression. The default is “Default”. This name must comply with the

file naming conventions as it is also the name for the file where the expression is stored.

Expression – Denotes the desired expression, which can be written easily using the calculator on the right side

and the lists of the available inputs above. Nevertheless, the syntax rules for the format of the expression are

detailed in 14.3. Any mathematically valid expression is allowed.

Output as – Determines what the output of the expression is used for – either as an additional Graph Data

Series (the usual use-case) or as a Variable to use in other expressions.

Physical Unit – Does not contribute to the expression itself. Merely determines the resultant type of the

expression and therefore sets the destination graph.

Category – Some output units have different variants such as being absolute or relative. This also only

determines the destination graph.

The sections below are included for better convenience of the user and may be fully replaced by a written text in the

Expression field:

Designation – Changes between the reference and the deformed designation of the input graph data. Most of

the time, the deformed value (the actually computed value for the position) is what is needed (hence it is the

default). However, for the computation of relative values (such as the elongation in units of percent),

a reference value is also required. Additionally, it is possible to input the deformed value from the previous

evaluated step in time, in which case the initial value is provided to determine the “previous” value in the first

step (reference).

Graph Data – Lists all available graph data in the project, including but not limited to the Force [N] from a testing

machine or the Excitation Frequency [Hz]. By double clicking, the name of the measured value is included in the



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Expression field along with all necessary parameters, all encapsulated by the tokens which determine the

selected designation. The values are always of the double type, see below.

Variables – Lists all available variables created as separate custom series with their output set as Variable. By

double clicking, their name is included in the Expression field, along with the tokens, which effectively substitute

this item with the result of the respective expression during evaluation. The selected designation is ignored in

this case.

When saving an expression, it is checked for syntax errors. This is either prompted automatically or performed manually

by clicking the Validate and Save button. If the check fails, a message box with detailed information is shown. The

expression is still added to the project and saved to a file and it is up to the user to correct it.

As previously shown in Figure 142, there is a sidebar with buttons in order to operate easily and intuitively. These contain

the supported operators and functions, whose detailed description is described in chapter 14.3 as a part of the supported

syntax.

14.2.3 Activating an Existing Expression The Active Custom Series box lists all available expressions, where each can easily be turned on and off by simply clicking

the check box to the left. The information about the activated expressions is saved into the project file. If there are

computed data already present when activating a series, the computed results of the evaluated expression will be shown

in the graph displays, so the project does not have to be recomputed.

An expression is saved into a file name.mxp under Documents\MercuryRT\expressions\.

14.2.4 Importing an Expression In the Custom Series window, click the Import button. A file selection dialog will appear, requesting the user to enter an

*.mxp file (see 14.5 for details). After importing the file, it is added into the user folder and to the displayed list in the UI.

14.2.5 Removing an Existing Expression

In the Custom Series window, click the Delete button. A confirmation dialog will appear. After deleting the expression, the

expression file from the disk is deleted as well and it will no longer be available to any projects.

14.3 Syntax

14.3.1 Naming Convention and Precedence Note: When the following table refers to a unique identifier of graph data, it refers either to a pair of a probe name and its

measured quantity (separated by a comma, such as #T1,DisplacementEuclidean#) or a separate measured value, which is

unrelated to any probes (for example #FrameRelativeTimeSeconds#). In case of the previous examples, it is necessary to

input these identifiers by double clicking the respective items in the list of Graph Data above the Expression field, but there

is also an option to use a custom alias in place of the entire identifier, thus simplifying the text of the expression (making

it read something like #Length1*# - #Length2*#).

Syntax Description



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$id$ Denotes a graph data value recognized by its specified unique

identifier. Non-changing reference values will be used in the

expression.

#id# Denotes a graph data value recognized by its specified unique

identifier. Varying deformed values will be used in the

expression.

&initValue,id& Denotes a graph data value recognized by its specified unique

identifier. Varying deformed values from the previous step in

time and an initial value of initValue will be used in the

expression.

@name@ Denotes a variable of the specified name.

( ) Determines the precedence of expression parts as per

standard mathematics, can be used anywhere.

Table 1: Naming convention and precedence.

14.3.2 Mathematical Operations Operation Description

val1 + val2 Returns the result of adding two values.

val1 – val2 Returns the result of subtracting two values.

val1 * val2 Returns the result of multiplying two values.

val1 / val2 Returns the result of dividing two values.

abs(value) Returns the absolute value of a number.

acos(d) Returns the angle in radians whose cosine is the

specified number.

asin(d) Returns the angle in radians whose sine is the

specified number.

atan(d) Returns the angle in radians whose tangent is the

specified number.

atan2(y, x) Returns the angle in radians whose tangent is the

quotient of two specified numbers.

ceiling(a) Returns the smallest integral value that is greater

than or equal to the specified floating-point

number.



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cos(a) Returns the cosine of the specified angle in

radians.

cosh(value) Returns the hyperbolic cosine of the specified

angle in radians.

exp(d) Returns e raised to the specified power.

floor(d) Returns the largest integer less than or equal to

the specified floating-point number.

log(d) Returns the natural (base e) logarithm of a

specified number.

log(a, newBase) Returns the logarithm of a specified number in a

specified base.

log10(d) Returns the base 10 logarithm of a specified

number.

max(val1, val2) Returns the larger of two numbers.

min(val1, val2) Returns the smaller of two numbers.

pow(x, y) Returns a specified number raised to the specified

power.

round(a) Rounds a floating-point value to the nearest

integral value.

sign(value) Returns a value indicating the sign of a number.

sin(a) Returns the sine of the specified angle in radians.

sinh(value) Returns the hyperbolic sine of the specified angle

in radians.

sqrt(d) Returns the square root of a specified number.

tan(a) Returns the tangent of the specified angle in

radians.

tanh(value) Returns the hyperbolic tangent of the specified

angle in radians.

truncate(d) Calculates the integral part of a specified floating-

point number.

Table 2: Lists all operations available for the computed values.



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14.3.3 Constants Constant Description

e, E Represent the natural logarithmic base, specified by the

constant, e.

pi, Pi, PI Represent the ratio of the circumference of a circle to its

diameter, specified by the constant, π.

Table 3: Lists all available constants.

14.3.4 Recursion In its current state, the Custom Series editor supports the input of recursive expressions, i.e. the ones which take the value

of the entire expression computed in the previous time step to compute a new value for the current time step. To do this,

it is required to put the special function written as previous(initValue) into the body of the expression, where initValue is

the initial value of this function in reference.

14.4 Examples

Expression Meaning

(#T1,DisplacementInZ# +

#T2,DisplacementInZ# +

#T3,DisplacementInZ#) / 3

Computes an average of

displacement in Z-axis from 3

points.

abs(#A2,LengthExtensionPercentage#/#A1,Le

ngthExtensionPercentage#)

Computes Poisson’s ratio from two

lines. 𝜈 =∆𝑇𝑟𝑎𝑛𝑠𝑣𝑒𝑟𝑠𝑒

∆𝐿𝑜𝑛𝑔𝑖𝑡𝑢𝑑𝑖𝑛𝑎𝑙

#A1,AngleToXAxisRadians#*3/#A1,LengthInX# Computes shear strain from one

line during torsion test. 𝜖 =𝜃𝑟

𝐿

(2*#TestingMachineLoadN#/(pi*exp(3)) Computes shear stress from testing

machine sensor. 𝜏 =2𝑇

𝜋𝑟3

Table 4: Lists examples of valid expressions.

14.5 Expression File Format

The expression file format *.mxp (Mercury RT Expression) is as follows:

<?xml>

<VE>

<VES>ExpressionString</VES>

<VEU>OutputUnit</VEU>

<VEC>UnitCategory</VEC>



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<VEV>IsVariable</VEV>

</VE>

where:

ExpressionString is the actual text representation of the expression as seen in the Expression field in the UI.

OutputUnit is the name of the output unit type.

UnitCategory is the category of the output unit.

IsVariable specifies whether the expression specifies a variable or not.

Please note that an expression may also be edited in a text editor directly if needed.

14.6 Troubleshooting

Problem Solution

When I enter a new

expression / modify an

existing one, an error is

reported.

Make sure the syntax of the expression is

mathematically correct, especially the number

of opening and closing brackets. Make sure the

name of the operations is supported as

specified in 14.3. The shown error message

usually describes the exact place where the

problem is.

I switched to another

project / measurement and

now my expression does not

show in the graphs.

Most likely the probe names mentioned in the

expression are not present in the current

project. The expression needs to be adjusted

accordingly.

My configured expression

does not show in the graphs.

See “When I enter a new expression / modify an

existing one, an error is reported”. Some

problems cannot be resolved when statically

entering an expression (i.e. just the syntax) and

will only manifest when used in computation.

The distance between two

points in two different

cameras is not correct.

The two cameras are not properly adjusted into

one reference frame. The coordinate systems

must correspond with each other.

Table 5: Lists occurrences of problems with custom expressions and the appropriate approaches to resolve them.



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Graph Configurator

Beside the possibility of editing existing series and creating new series, Mercury RTⓇ also allows to configure graphs

according to custom requirements. This chapter describes the workflow behind the creation and configuration of such

graphs.

15.1 Graph Configurator Access

The Graph Configurator window is accessed by selecting the Graph Configurator option in the graph panel’s context menu

from the main window as shown in Figure 143.

Figure 143: Access to the Graph Configurator from the main window.

Figure 144: The Graph Configurator window.



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15.2 Adding a New Graph

The procedure of creating a new graph is as follows. The new graph is added by clicking the Create button seen in the

bottom left of Figure 144. The name of the graph is entered into the Name box at the top. The first step is to choose the

appropriate units on the X a Y axes. Then the categories of these units are selected if available. Mind that only the

computed (output) or the input value units are accessible. Individual variables can be chosen after clicking the Add New

Series button, which opens the Select Series dialog. As evident in Figure 145, the Select Series dialog offers variables

related to their units and categories for each axis. Note that the default graphs are labelled “Read Only” and cannot be

edited except for their Graph Annotations described in the following chapter.

Figure 145: Selecting Series in the Graph Configurator window.

15.3 Graph Annotations

The Graph Annotations grid is located in the bottom part of the Graph Configurator window as previously seen in Figure

144. It provides several sets of optional parameters for custom adjustment. The graph annotations settings are as follows:

Minimum and maximum of minimal scale of Y-axis – Defines the minimum of the minimal scale of the Y-axis in

unit, which defines the preset. A value of zero calculates the scale of the Y-axis automatically.

Series maximum and minimum – Includes the options Enabled and Label.

Linear regression – These are available primarily to analyze the yield strength and Young’s modulus of elasticity.

o Yield strength analysis enabled – Enables or disables the computation of Young’s modulus.

o Selected Axis – The axis, which is used for data filtering between “Minimal value” and “Maximal value”.

o Relative – Indicates whether Minimal and Maximal values are absolute or relative.



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o Minimal and maximal value [%] – Defines the range of values in selected axis used for computation of

linear regression (Young’s modulus). Young’s modulus is computed as a tangent of a straight curve

fitting linear part of stress-strain graph based on the least square method. Range of its computation is

defined by the axis interval of which the minimal and maximal values might be altered. The default axis

limit values are 20 % and 80 %. This adjustment is very useful because different materials are

distinguished by various stress-strain graphs and therefore, fitting limits are needed to be changed

appropriately to obtain an acceptable Young’s modulus value.

o Factor – Multiplying factor which is applied for displayed value of slope of linear regression line.

o Enabled – Indicates whether the annotation is shown in the graph.

o Label – Defines a label shown next to the computed values.

User defined annotations – Allows to make annotations on a chosen axis. Defines position and text label, which

should be shown in graph.

o Selected Axis – Can either be the X Axis or the Y Axis.

o Position – The position of the annotation.

o Enabled – Indicates whether the annotation is shown in the graph.

o Label – The text label of the annotation.

15.4 Stress vs. Strain Graph

As shown in Figure 146, a stress vs. strain graph can be used to evaluate common material properties. The X-axis shows

the deformation of the sample computed using probes capable of tracking extension, while the Y-axis displays the value

of stress computed from the measured force and the cross-section area of the measured sample. Input of the cross-section

area is accessed by right-clicking on the probes used for such measurement. The values of true stress and true strain can

also be evaluated by using this graph if they are selected for measurement using the context menu of the relevant probes,

but these values are only valid until the beginning of necking. For example, the evaluation of Young’s modulus may be

adjusted under the Linear Regression settings in this window. Alternatively, a custom copy of the stress vs. strain graph

can be created here as well. This graph is automatically available when Mercury RTⓇ is connected to a DOLI test rig,

receives force data and stress/strain computation is enabled.



139

Figure 146: Stress vs. strain graph of a low-carbon steel.



140

Appendix A. Mercury RTⓇ LiteView

The lite version of the user interface is primarily designed for the usage in industry. A shortcut called “MercuryRT

LiteView” launches this version. It supports all scene types and I/O services for a remote control and the output of values.

Only the left camera of a pair is displayed in a stereo mode. LiteView only offers to work in a live mode, which means that

there is only a button corresponding to the Run button and no such thing as a Recompute button. The project files are

referred to in LiteView as Presets and are open as read-only in that they cannot be modified in any way.

The first preset is loaded automatically from the selected preset folder, path of which is specified as a startup parameter

of UI.Launcher.exe. Alternatively, the folder can be selected by the button highlighted in orange in Figure 147. The

individual presets located in this folder can be selected from the drop-down menu highlighted in red. The function of the

prominently colored Start button is the same as of the Run button in the standard UI.

Figure 147: The Mercury RTⓇ LiteView program.

It is permitted to move the probes in the scene to be able to specify a proper position before a measurement. In a 2D

scene, the camera is always rotated that the X-axis is headed to the right side and the Y-axis is headed to the top and

additionally, the rotation of the view from the original project is applied as well. As an information about the associated

I/O services, there are light indicators on the right of the individual measured values. The active outputs are displayed in

the box in the lower left corner.



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Appendix B. Troubleshooting

Always adjust the parameters of the correlation that is causing the problem:

Adjust Correlation in Time (see 7.3.1.1) if experiencing problems with the computation between the reference

frame and deformed frames.

Adjust Stereo Pair Correlation (see 7.3.1.2) if experiencing problems with the computation between the left and

the right frame (note that the stereo pair correlation is being done only in the reference frame pair and then

two correlations in time are performed for both sides).

Adjust Width Correlation (see 7.3.2.3) if experiencing problems with the computation of width points.

Problem Solution

Some probes have not

been computed

Increase the template size so that template

contains more information. Keep in mind that

local deformations inside templates cannot be

detected accurately.

Adjust the correlated parameters. For example,

omnidirectional translate is enough when

specimen only moves. The fewer parameters are

being correlated, the less information is required

to correlate them.

Increase the confidence interval or the maximum

square residual per pixel. This is usually required

when light conditions are changing during the

measurement or when the measured surface

changes drastically.

If full-field analysis is being done on an

unconnected surface, try turning off automatic

filtration (see 7.3.4).

If probes have been not computed in the right

camera while being added, try dragging them in

the right camera close to their correct locations.

Some probes have been

computed in incorrect

locations

Increase the template size. This increases the

chance that the algorithm will be able to

differentiate between the reference and the

incorrect location.

Adjust the correlated parameters. For example,

when tracking an edge, try correlation of a

translation in the direction perpendicular to the

direction of the edge because for the algorithm all

positions on the edge are correct.

Decrease the confidence interval or the maximum

square residual per pixel. This increases chance of

incorrect locations being rejected.

If full-field analysis is being done on a connected

surface, try turning on automatic filtration (see

7.3.4). This will filter out points with



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transformations that do not match

transformations of the surrounding points.

If more than one location seems to be correct

solution, change the correlation speed to fastest

or fast to limit the searched area. Also try

removing the repeating pattern from the

measured specimen.

If incorrect locations have been computed in the

right camera while adding probes, try dragging

probes in the right camera close to their correct

locations.

Table 6: Solutions of the most common problems.



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Appendix C. Tips and Tricks

Measurement of Poisson’s Ratio

Many users struggle to measure the Poisson’s ratio. This paragraph provides advice on how to measure the Poisson’s ratio

in Mercury RTⓇ as accurately as possible. The reasons behind incorrect results are as follows:

1) The edges of the specimen are skewed by lighting.

2) The transversal contraction is very low compared to its longitudinal extension.

3) The specimen moves out of the measuring plane.

The suggested solutions are mentioned in paragraphs below.

i. Specimen Edges Skewed by Lighting

The reflections of the lighting on the edges of the specimen can make measuring width less accurate. To avoid this problem,

move the width templates from the edges to the body of the specimen. This is applicable only if using width measuring

probes.

ii. Low Transversal Contraction Value

Many specimens are too narrow to measure the transversal contraction with common lens at a normal working distance.

To increase the resolution of the measurement, it is necessary to use a camera with a higher resolution, lens with a higher

focal length or decrease the working distance. This requires to lower the focus distance, which can be done using a macro

lens or normal lens with an extension tube.

iii. Specimen Out of the Measuring Plane

Some testing machines do not keep the motion of the specimen sufficiently in the reference plane. The displacement of

the specimen to another plane, which is not parallel to the reference plane, may devalue especially the transversal

contraction and thus the value of the Poisson’s ratio. The best solution is to switch to a stereo scene instead of a mono

scene. Then, the Poisson’s ratio can be computed using two line probes and setting an appropriate expression in the

Custom Series (Expression Editor) window shown in Figure 142.



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Appendix D. Keyboard Shortcuts

Available in the main window:

Ctrl + N New project

Ctrl + O Open project

Ctrl + S Save project

Ctrl + Shift + S Save project as

Available in a camera display:

F1 Point probe

F2 Rigid plane probe

F3 Line probe

F4 Chain probe

F5 Polyline probe

F6 Force gauge

F7 Point group

F8 Neck gauge

F9 Strain gauge (mono) / Surface (stereo)

F10 Area: Include

F11 Area: Exclude

F12 PIV field

C Clippings and histogram

I Invert colors

P Pseudo colors

Ctrl + H Flip image horizontally

Ctrl + V Flip image vertically

Ctrl + L Rotate image left

Ctrl + R Rotate image right

Ctrl + I Hide labels

Ctrl + P Hide probes

Ctrl + C Copy camera view to clipboard (also available in graph displays and 3D graph)

Page Up Previous picture

Page Down Next picture



145

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